Cirrus Logic CS42L51 User Manual

CS42L51

Low Power, Stereo CODEC with Headphone Amp

DIGITAL to ANALOG FEATURES

 98 dB Dynamic Range (A-wtd)  -86 dB THD+N  Headphone Amplifier - GND Centered

– On-Chip Charge Pump Provides -VA_HP – No DC-Blocking Capacitor Required – 46 mW Power Into Stereo 16 Ω @ 1.8 V – 88 mW Power Into Stereo 16 Ω @ 2.5 V – -75 dB THD+N

 Digital Signal Processing Engine

– Bass & Treble Tone Control, De-Emphasis – PCM + ADC Mix w/Independent Vol Control – Master Digital Volume Control – Soft Ramp & Zero Cross Transitions

 Beep Generator

– Tone Selections Across Two Octaves – Separate Volume Control – Programmable On & Off Time Intervals – Continuous, Periodic or One-Shot Beep

Selections

 Programmable Peak-Detect and Limiter  Pop and Click Suppression

ANALOG to DIGITAL FEATURES

 98 dB Dynamic Range (A-wtd)  -88 dB THD+N  Analog Gain Controls

– +32 dB or +16 dB MIC Pre-Amplifiers – Analog Programmable Gain Amplifier

(PGA)

 +20 dB Digital Boost  Programmable Automatic Level Control (ALC)

– Noise Gate for Noise Suppression – Programmable Threshold and

Attack/Release Rates

 Independent Channel Control  Digital Volume Control  High-Pass Filter Disable for DC Measurements  Stereo 3:1 Analog Input MUX  Dual MIC Inputs

– Programmable, Low Noise MIC Bias Levels – Differential MIC Mix for Common Mode

Noise Rejection

 Very Low 64 Fs Oversampling Clock Reduces

Power Consumption

1.8 V to 3.3 V

Serial Audio

Input

Hardware

Mode or I

C &

SPI Software

Mode

Control Data

Reset

Serial Audio

Output

Level Translator

http://www.cirrus.com

1.8 V to 2.5 V 1.8 V to 2.5 V

MUX

Digital

Generator

PCM Serial Interface

Configuration

Beep

High Pass

Filters

Signal

Processing

Engine

ALC

Volume

Controls

MUX

Multibit

∆Σ Modulator

Multibit

Oversampling

ADC

Multibit

Oversampling

ADC

Switched

Capacitor DAC

and Filter

Switched

Capacitor DAC

and Filter

MUX

PGA

MUX

PGA

1.8 V to 2.5 V

Headphone Amp - GND

Centered

Headphone Amp - GND

Centered

MUX

Charge

Pump

+32 dB

MIC Bias

Left HP Out

Right HP Out

Stereo Input 1 Stereo Input 2

Stereo Input 3 / Mic Input 1 & 2

JULY '06 DS679F1

CS42L51

SYSTEM FEATURES

 24-bit Converters  4 kHz to 96 kHz Sample Rate  Multi-bit Delta Sigma Architecture  Low Power Operation

– Stereo Playback: 12.93 mW @ 1.8 V – Stereo Record and Playback: 20.18 mW @

1.8 V

 Variable Power Supplies

– 1.8 V to 2.5 V Digital & Analog – 1.8 V to 3.3 V Interface Logic

 Power Down Management

– ADC, DAC, CODEC, MIC Pre-Amplifier,

PGA

 Software Mode (I²C  Hardware Mode (Stand-Alone Control)  Digital Routing/Mixes:

– Analog Out = ADC + Digital In – Digital Out = ADC + Digital In – Internal Digital Loopback – Mono Mixes

 Flexible Clocking Options

– Master or Slave Operation – High-Impedance Digital Output Option (for

easy MUXing between CODEC and Other Data Sources)

– Quarter-Speed Mode - (i.e. Allows 8 kHz Fs

while maintaining a flat noise floor up to 16 kHz)

APPLICATIONS

 HDD & Flash-Based Portable Audio Players  MD Players/Recorders  PDAs  Personal Media Players  Portable Game Consoles  Digital Voice Recorders  Digital Camcorders  Digital Cameras  Smart Phones

& SPI™ Control)

GENERAL DESCRIPTION

The CS42L51 is a highly integrated, 24-bit, 96 kHz, low power stereo CODEC. Based on multi-bit, delta-sigma modulation, it allows infinite sample rate adjustment between 4 kHz and 96 kHz. Both the ADC and DAC offer many features suitable for low power, portable system applications.

The ADC input path allows independent channel control of a number of features. An input multiplexer selects between line-level or microphone level inputs for each channel. The microphone input path includes a selectable programmable-gain pre-a mplifier stage and a low noise MIC bias voltage supply. A PGA is available for line or microphone inputs and provides analog gain with soft ramp and zero cross transitions. The ADC also features a digital volume attenuator with soft ramp transitions. A programmable ALC and Noise Gate monitor the input signals and adjust the volume levels appropriately.

The DAC output path includes a digital signal pro cessing engine. Tone Control provides bass and treble adjustment of four selectable corner frequencies. The Mixer allows independent volume control for both the ADC mix and the PCM mix, as well as a master digital volume control for the analog output. All volume level changes may be configured to occur on soft ramp and zero cross transitions. The DAC also includes de-emphasis, limiting functions and a beep generator delivering tones selectable across a range of two full octaves.

The stereo headphone amplifier is powered from a separate positive supply and the integrated charge pump provides a negative supply. This allows a gr ound-centered analog output with a wide signal swing and eliminates external DC-blocking capacitors.

In addition to its many features, the CS42L51 operates from a low-voltage analog and digital core, making this CODEC ideal for portable systems that require extremely low power consumption in a minimal amount of space.

The CS42L51 is available in a 32-pin QFN package in both Commercial (-10 to +70° C) and Automotive grades (-40 to +85° C). The CDB42L51 Customer Demonstration board is also available for device evaluation and implementation suggestions. Please see “Ordering

Information” on page 85 for complete details.

2 DS679F1

TABLE OF CONTENTS

1. PIN DESCRIPTIONS - SOFTWARE (HARDWARE) MODE ..................................................................7

1.1 Digital I/O Pin Characteristics ........................................................................................................... 9

2. TYPICAL CONNECTION DIAGRAMS .................................................................................................10

3. CHARACTERISTIC AND SPECIFICATION TABLES ......................................................................... 12

SPECIFIED OPERATING CONDITIONS ............................................................................................. 12

ABSOLUTE MAXIMUM RATINGS .......................................................................................................12

ANALOG INPUT CHARACTERISTICS (COMMERCIAL - CNZ) .......................................................... 13

ANALOG INPUT CHARACTERISTICS (AUTOMOTIVE - DNZ) ..........................................................14

ADC DIGITAL FILTER CHARACTERISTICS .................................................................... ... .... ... ... ... ... 15

ANALOG OUTPUT CHARACTERISTICS (COMMERCIAL - CNZ) ...................................................... 16

ANALOG OUTPUT CHARACTERISTICS (AUTOMOTIVE - DNZ) ................ ... ................................... 17

LINE OUTPUT VOLTAGE CHARACTERISTICS ................................................................................. 18

HEADPHONE OUTPUT POWER CHARACTERISTICS ................................................ ... ... .... ... ... ... ... 19

COMBINED DAC INTERPOLATION & ON-CHIP ANALOG FILTER RESPONSE .............................. 20

SWITCHING SPECIFICATIONS - SERIAL PORT ............................................................................... 20

SWITCHING SPECIFICATIONS - I²C® CONTROL PORT .................................................................. 22

SWITCHING CHARACTERISTICS - SPI™ CONTROL PORT ............................................................ 23

DC ELECTRICAL CHARACTERISTICS .............................................................................................. 24

DIGITAL INTERFACE SPECIFICATIONS & CHARACTERISTICS ..................................................... 24

POWER CONSUMPTION .................................................................................................................... 25

4. APPLICATIONS ...................................................................................................................................26

4.1 Overview .........................................................................................................................................26

4.1.1 Architecture ........................................................................................................................... 26

4.1.2 Line & MIC Inputs ..................................................................................................................26

4.1.3 Line & Headphone Outputs ................................................................................................... 26

4.1.4 Signal Processing Engine ..................................................................................................... 26

4.1.5 Beep Generator .....................................................................................................................26

4.1.6 Device Control (Hardware or Software Mode) ...................................................................... 26

4.1.7 Power Management .............................................................................................................. 26

4.2 Hardware Mode .............................................................................................................................. 27

4.3 Analog Inputs ................................................................................................................................. 28

4.3.1 Digital Code, Offset & DC Measurement ...............................................................................28

4.3.2 High-Pass Filter and DC Offset Calibration ........................................................................... 29

4.3.3 Digital Routing ....................................................................................................................... 29

4.3.4 Differential Inputs .................................................................................................................. 29

4.3.4.1 External Passive Components ......... ....... ...... ....... ...... ... ....... ...... ....... ...... ....... ...... ...... 29

4.3.5 Analog Input Multiplexer ........................................................................................................ 31

4.3.6 MIC & PGA Gain ...................................................................................................................31

4.3.7 Automatic Level Control (ALC) .............................................................................................. 32

4.3.8 Noise Gate ............................................................................................................................ 33

4.4 Analog Outputs ............................................................................................................................... 34

4.4.1 De-Emphasis Filter ................................................................................................................34

4.4.2 Volume Controls ....................................................................................................................35

4.4.3 Mono Channel Mixer ............................................................................................................. 35

4.4.4 Beep Generator .....................................................................................................................35

4.4.5 Tone Control .......................................................................................................................... 36

4.4.6 Limiter .................................................................................................................................... 36

4.4.7 Line-Level Outputs and Filtering ........................................................................................... 37

4.4.8 On-Chip Charge Pump ..........................................................................................................38

4.5 Serial Port Clocking ........................................................................................................................ 38

4.5.1 Slave ..................................................................................................................................... 39

4.5.2 Master ................................................................................................................................... 39

CS42L51

DS679F1 3

CS42L51

4.5.3 High-Impedance Digital Output ............................................................................................. 40

4.5.4 Quarter- and Half-Speed Mode .............................................................................................40

4.6 Digital Interface Formats ................................................................................................................ 40

4.7 Initialization ..................................................................................................................................... 41

4.8 Recommended Power-Up Sequence ............................................................................................. 41

4.9 Recommended Power-Down Sequence ........................................................................................ 42

4.10 Software Mode .............................................................................................................................43

4.10.1 SPI Control .......................................................................................................................... 43

4.10.2 I²C Control ........................................................................................................................... 43

4.10.3 Memory Address Pointer (MAP) .......................................................................................... 45

4.10.3.1 Map Increment (INCR) ............................................................................................. 45

5. REGISTER QUICK REFERENCE ........................................................................................................ 46

6. REGISTER DESCRIPTION .................................................................................................................. 49

6.1 Chip I.D. and Revision Register (Address 01h) (Read Only) .........................................................49

6.2 Power Control 1 (Address 02h) ......................................................................................................49

6.3 MIC Power Control & Speed Control (Address 03h) ...................................................................... 50

6.4 Interface Control (Address 04h) ..................................................................................................... 52

6.5 MIC Control (Address 05h) .............................................................................................................53

6.6 ADC Control (Address 06h) ............................................................................................................54

6.7 ADCx Input Select, Invert & Mute (Address 07h) ........................................................................... 56

6.8 DAC Output Control (Address 08h) ................................................................................................ 57

6.9 DAC Control (Address 09h) ............................................................................................................58

6.10 ALCX & PGAX Control: ALCA, PGAA (Address 0Ah) & ALCB, PGAB (Address 0Bh) ............... 59

6.11 ADCx Attenuator: ADCA (Address 0Ch) & ADCB (Address 0Dh) ................................................ 60

6.12 ADCx Mixer Volume Control: ADCA (Address 0Eh) & ADCB (Address 0Fh) .............................. 61

6.13 PCMX Mixer Volume Control:

PCMA (Address 10h) & PCMB (Address 11h) ..................................................................................... 62

6.14 Beep Frequency & Timing Configuration (Address 12h) .............................................................. 62

6.15 Beep Off Time & Volume (Address 13h) ...................................... ... .... ... ... ... .... ... ... ... ... ................63

6.16 Beep Configuration & Tone Configuration (Address 14h) ............................................................ 64

6.17 Tone Control (Address 15h) ......................................................................................................... 65

6.18 AOUTx Volume Control:

AOUTA (Address 16h) & AOUTB (Address 17h) ................................................................................. 66

6.19 PCM Channel Mixer (Address 18h) .............................................................................................. 67

6.20 Limiter Threshold SZC Disable (Address 19h) ............................................................................. 67

6.21 Limiter Release Rate Register (Address 1Ah) .............................................................................. 69

6.22 Limiter Attack Rate Register (Address 1Bh) .................................................................................70

6.23 ALC Enable & Attack Rate (Address 1Ch) ................................................................................... 70

6.24 ALC Release Rate (Address 1Dh) ................ ............. ............. ............. ............. ............ ................ 71

6.25 ALC Threshold (Address 1Eh) ...................................................................................................... 71

6.26 Noise Gate Configuration & Misc. (Address 1Fh) ......................................................................... 72

6.27 Status (Address 20h) (Read Only) ............................................................................................... 73

6.28 Charge Pump Frequency (Address 21h) ...................................................................................... 74

7. ANALOG PERFORMANCE PLOTS .......... ... .... ... ... ... .... ... .......................................................... ... ......75

7.1 Headphone THD+N versus Output Power Plots ............................................................................75

7.2 Headphone Amplifier Efficiency ...................................................................................................... 77

7.3 ADC_FILT+ Capacitor Effects on THD+N ...................................................................................... 78

8. EXAMPLE SYSTEM CLOCK FREQUENCIES .................................................................................... 79

8.1 Auto Detect Enabled ....................................................................................................................... 79

8.2 Auto Detect Disabled ...................................................................................................................... 80

9. PCB LAYOUT CONSIDERATIONS ..................................................................................................... 81

9.1 Power Supply, Grounding ............................................................................................................... 81

9.2 QFN Thermal Pad .......................................................................................................................... 81

10. ADC & DAC DIGITAL FILTERS ........................................................................................................ 82

4 DS679F1

11. PARAMETER DEFINITIONS .............. ... ... ... .... ... ... ... .... ... ....................................................... ............83

12. PACKAGE DIMENSIONS .......... .... ... ... ... ... .... ... ....................................................... ... ... ... .... ............84

THERMAL CHARACTERISTICS ........................................................................................................84

13. ORDERING INFORMATION .......... ... ... ... ... .... ... ... ... .... ... ... ... ............................................................. 85

14. REFERENCES ....................... ... ... .... ... ... ... ... .... ... ... ....................................................... ...................... 85

15. REVISION HISTORY ......... ... ... ... .... ... ... ... ... .... ....................................................... ... ... ... ................... 86

LIST OF FIGURES

Figure 1.Typical Connection Diagram (Software Mode) ........................................................................... 10

Figure 2.Typical Connection Diagram (Hardware Mode) .......................................................................... 11

Figure 3.Headphone Output Test Load ..................................................................................................... 19

Figure 4.Serial Audio Interface Slave Mode Timing .................................................................................. 21

Figure 5.Serial Audio Interface Master Mode Timing ................................................................................ 21

Figure 6.Control Port Timing - I²C ............................................................................................................. 22

Figure 7.Control Port Timing - SPI Format ................................................................................................ 23

Figure 8.Analog Input Architecture ............................................................................................................ 28

Figure 9.MIC Input Mix w/Common Mode Rejection .................................................................................30

Figure 10.Differential Input ........................................................................................................................ 30

Figure 11.ALC ...........................................................................................................................................32

Figure 12.Noise Gate Attenuation .............................................................................................................33

Figure 13.Output Architecture ................................................................................................................... 34

Figure 14.De-Emphasis Curve ..................................................................................................................35

Figure 15.Beep Configuration Options ...................................................................................................... 36

Figure 16.Peak Detect & Limiter ...............................................................................................................37

Figure 17.Master Mode Timing ................................................................................................................. 39

Figure 18.Tri-State Serial Port ..................... ... ... .... ... ... ... .... ... ... ... .... ... ... ... ... ............................................. 40

Figure 19.I²S Format .................................................................................................................................40

Figure 20.Left-Justified Format .................................................................................................................41

Figure 21.Right-Justified Format (DAC only) ............................................................................................ 41

Figure 22.Initialization Flowchart ............................................................................................................... 42

Figure 23.Control Port Timing in SPI Mode ..................................................................................... .........43

Figure 24.Control Port Timing, I²C Write ...................................................................................................44

Figure 25.Control Port Timing, I²C Read ................................................................................................... 44

Figure 26.AIN & PGA Selection ................................................................................................................56

Figure 27.THD+N vs. Output Power per Channel at 1.8 V (16 Ω load) .................................................... 75

Figure 28.THD+N vs. Output Power per Channel at 2.5 V (16 Ω load) .................................................... 75

Figure 29.THD+N vs. Output Power per Channel at 1.8 V (32 Ω load) .................................................... 76

Figure 30.THD+N vs. Output Power per Channel at 2.5 V (32 Ω load) .................................................... 76

Figure 31.Power Dissipation vs. Output Power into Stereo 16 Ω ......................................................................77

Figure 32.Power Dissipation vs. Output Power into Stereo 16 Ω (Log Detail) .... ... ... .... ... ......................... 77

Figure 33.ADC THD+N vs. Frequency w/Capacitor Effects ...................................................................... 78

Figure 34.ADC Passband Ripple ........................................................ ... ... ................................................ 82

Figure 35.ADC Stopband Rejection .......................................................................................................... 82

Figure 36.ADC Transition Band ................................................................................................................82

Figure 37.ADC Transition Band Detail ...................................................................................................... 82

Figure 38.DAC Passband Ripple ........................................................ ... ... ... .... ... ...................................... 82

Figure 39.DAC Stopband .......................................................................................................................... 82

Figure 40.DAC Transition Band ................................................................................................................82

Figure 41.DAC Transition Band (Detail) .................................................................................................... 82

CS42L51

DS679F1 5

LIST OF TABLES

Table 1. I/O Power Rails ............................................................................................................................. 9

Table 2. Hardware Mode Feature Summary ............................................................................................. 27

Table 3. MCLK/LRCK Ratios .................................................................................................................... 39

CS42L51

6 DS679F1

1. PIN DESCRIPTIONS - SOFTWARE (HARDWARE) MODE

)

CS42L51

SDIN

LRCK

SDA/CDIN (MCLKDIV2)

SCL/CCLK (I²S/LJ

ADO/CS

(DEM) VA_HP

FLYP

GND_HP

FLYN

SCLK

MCLK

SDOUT (M/S

DGND

303132

)

CS42L51

109

AOUTA

AOUTB

VSS_HP

13 14 15 16

AGND

DAC_FILT+

262728

Pin Name # Pin Description

Left Right Clock (Input/Output) - Determines which channel, Left or Right, is currently active on the

LRCK

SDA/CDIN (MCLKDIV2)

SCL/CCLK

)

(I²S/LJ

AD0/CS (DEM)

VA_HP FLYP GND_HP FLYN

VSS_HP

serial audio data line. Serial Control Data (Input/Output) - SDA is a data I/O in I²C Mode. CDIN is the input data line for the

control port interface in SPI Mode.

MCLK Divide by 2 (Input) - Hardware Mode: Divides the MCLK by 2 prior to all internal circuitry. Serial Control Port Clock (Input) - Serial clock for the serial control port.

Interface Format Selection (Input) - Hardware Mode: Selects between I²S & Left-Justified interface for- mats for the ADC & DAC.

Address Bit 0 (I²C) / Control Port Chip Select (SPI) (Input) - AD0 is a chip address pin in I²C Mode; CS is the chip-select signal for SPI format.

De-Emphasis (Input) - Hardware Mode: Enables/disables the de-emphasis filter.

Analog Power For Headphone (Input) - Positive power for the internal analog headphone section.

Charge Pump Cap Positive Node (Input) - Positive node for the external charge pump capacitor.

Analog Ground (Input) - Ground reference for the internal headphone/charge pump section.

Charge Pump Cap Negative Node (Input) - Negative node for the external charge pump capacitor. Negative Voltage From Charge Pump (Output) - Negative voltage rail for the internal analog head-

phone section.

RESET

AIN1B

AIN1A

AFILTB

AFILTA

AIN2B/BIAS AIN2A

MICIN2/BIAS/AIN3B

MICIN1/AIN3A

ADC_FILT+

DS679F1 7

CS42L51

AOUTB AOUTA

VA AGND DAC_FILT+ VQ ADC_FILT+ MICIN1/

AIN3A MICIN2/

BIAS/AIN3B

AIN2A

AIN2B/BIAS

AFILTA AFILTB

AIN1A AIN1B

RESET VL VD

DGND

SDOUT

)

(M/S

MCLK SCLK SDIN Thermal Pad

Analog Audio Output (Output) - The full-scale output level is specified in the DAC Analog Characteris-

tics specification table

Analog Power (Input) - Positive power for the internal analog section.

Analog Ground (Input) - Ground reference for the internal analog section.

Positive Voltage Reference (Output) - Positive reference voltage for the internal sampling circuits.

Quiescent Voltage (Output) - Filter connection for internal quiescent voltage.

Positive Voltage Reference (Output) - Positive reference voltage for the internal sampling circuits. Microphone Input 1 (Input) - The full-scale level is specified in th e ADC Analog Characteristics specifi-

cation table. Microphone Input 2 (Input/Output) - The full-scale level is specified in the ADC Analog Characteristics

specification table. This pin can also be configured as an output to provide a low noise bias supply for an external microphone. Electrical characteristics are specified in the DC Electrical Characteristics table.

Analog Input (Input) - The full-scale level is specified in the ADC Analog Characteristics specification

table. Analog Input (Input/Output) -

cation table. This pin can also be configured as an output to provide a low noise bias supply for an external microphone. Electrical characteristics are specified in the DC Electrical Characteristics table.

Filter Connection (Output) - Filter connection for the ADC inputs.

22 23

Analog Input (Input) - The full-scale level is specified in the ADC Analog Characteristics specification

table.

Reset (Input) - The device enters a low power mode when this pin is driven low. Digital Interface Power (Input) - Determines the required signal level for the serial audio interface and

host control port. Refer to the Recommended Operating Conditions for appropriate voltages.

Digital Power (Input) - Positive power for the internal digital section.

Digital Ground (Input) - Ground reference for the internal digital section. Serial Audio Data Output (Output) - Output for two’s complement serial au d io da ta.

Serial Port Master/Slave (Input/Output) - Hardware Mode Startup Option: Selects between Master and Slave Mode for the serial port.

Master Clock (Input) - Clock source for the delta-sigma modulators.

Serial Clock (Input/Output) - Serial clock for the serial audio interface.

Serial Audio Data Input (Input) - Input for two’s complement serial audio data.

Thermal relief pad for optimize d he a t di ssi pation. See “QFN Thermal Pad” on page 81.

The full-scale level is specified in the ADC Analog Characteristics specifi-

8 DS679F1

1.1 Digital I/O Pin Characteristics

The logic level for each input should not exceed the maximum ratings for the VL power supply.

CS42L51

Pin Name

SW/(HW)

RESET Input

SCL/CCLK

)

(I²S/LJ

SDA/CDIN

(MCLKDIV2)

AD0/CS

(DEM)

MCLK Input LRCK Input/Output SCLK Input/Output

SDOUT

)

(M/S SDIN Input

Input

Input/Output

Input

Input/Output

I/O Driver Receiver

- 1.8 V - 3.3 V

- 1.8 V - 3.3 V, with Hysteresis

1.8 V - 3.3 V, CMOS/Open Drain 1.8 V - 3.3 V, with Hysteresis

- 1.8 V - 3.3 V

1.8 V - 3.3 V, CMOS 1.8 V - 3.3 V

- 1.8 V - 3.3 V

Table 1. I/O Power Rails

DS679F1 9

2. TYPICAL CONNECTION DIAGRAMS

+1.8 V o r +2.5 V

See Note 5

* *Use low ESR ceramic capacitors.

Note 2 :

For best response to Fs/2 :

This circuitry is intended fo r applications where the CS42L51 connects directly to an unbalanced output of the device. For internal routing applications please see the DAC Analog Output Cha racteristics section for loading limitations.

Note 5 :

Larger capacitors, such as 1.5 µF, improves the charge pump performance (and subsequent THD+N) at the full scale output power achieved with gain (G) settings greater than default.

470×+

ext

()

RFs

ext

1.5 µF

4704

1 µF

Digital Audio

Processor

2 k

Ω

+1.8 V, +2.5 V

See Note 1

or +3.3 V

Note 1: Resistors are required for I²C control port operation

Ω

0.1 µF

FLYP FLYN VSS_HP

GND_HP

CS42L51

MCLK SCLK LRCK SDIN SDOUT RESET SCL/CCLK SDA/CDIN AD0/CS

DGND

0.1 µF

AIN3B/MICIN2

ADC_FILT+ DAC_FILT+

VA_HP

AOUTB

AOUTA

AIN1A

AIN1B

AIN2A

AIN2B

BIAS1

MICIN1

AIN3A

BIAS2

AGND

AFILTA AFILTB

0.1 µF

1800 pF

* Capacitors must be C0G or equivalent

0.022 µF

51.1 Ω

1 µF

0.1 µF

150 pF

1 µF

See Note 4

+1.8 V or +2.5 V

Note 4: Series resistance in the path of the power supplies must be avoided. Any voltage drop on VA_HP will dir ectly impact the negative charge pump supply (VSS_HP) and result in clipping on the audio output .

Headphone Out Left & Right

470

Ω

Line Level Out Left & Right

See Note 2

470

Ω

Speaker Driver

Left Analog Input 1

100 Ω

100 kΩ

100 Ω

100 kΩ

Note 3: The value of RL is dictated by the microphone cartridge.

1 µF

150 pF

Right Analog Input 1

Left Analog Input 2

100 kΩ

Right Analog Input 2

Microphone Input

Microphone Bias

See Note 3

10 µF

1 µF

CS42L51

ext

Figure 1. Typical Connection Diagram (Software Mode)

10 DS679F1

CS42L51

+1.8V or +2.5V

* *Use low ESR ceramic capacitors.

Digital Audio

Processor

+1.8V, 2.5 V

or +3.3V

(1) Pull-up to VL (47 kΩ for Master Mode.

Pull-down to DGND for Slave Mode.

1 µF

VL or DGND (1)

0.1 µF

FLYP FLYN VSS_HP

GND_HP

MCLK SCLK LRCK SDIN

SDOUT/ M/S

RESET I²S/LJ MCLKDIV2

DEM

CS42L51

DGND

0.1 µF

VA_HP

AOUTB

AOUTA

AIN1A

AIN1B

0.1 µF

1800 pF

0.022 µF

51.1 Ω

See Note 4

1 µF

Note 4: Series resistance in the path of the power supplies (typically used for added filtering) must be avoided. Any voltage drop on VA_HP will directly impact the negative charge pump supply (VSS_HP) and result in clipping on the audio output .

470Ω

100 Ω

1 µF

100 Ω

1 µF

+1.8V or +2.5V

Line Level Out Left & Right

See Note 2

Speaker Driver

Left Analog Input 1

100 kΩ

Right Analog Input 1

Headphone Out Left & Right

ext

ADC_FILT+ DAC_FILT+

AGND

AFILTA AFILTB

1 µF

* Capacitors must be C0G or equivalent

150 pF

10 µF

1 µF

Note 2 :

This circuitry is intended for applications where the CS 42L51 connects directly to an unbalanced output of the device . For internal routing applications please see the DAC Analog Output Characteristics section for loading limitations .

470×+

ext

For best response to Fs/2 :

()

RFs

ext

4704

Figure 2. Typical Connection Diagram (Hardware Mode)

DS679F1 11

CS42L51

3. CHARACTERISTIC AND SPECIFICATION TABLES

(All Min/Max characteristics and specifications are guaranteed over the Specified Operating Conditions. Typical performance characteristics and specifications are derived from measurements taken at nominal supply voltages and T

= 25° C.)

SPECIFIED OPERATING CONDITIONS

(AGND=DGND=0 V, all voltages with respect to ground.)

Parameters Symbol Min Nom Max Units

DC Power Supply (Note 1) Analog Core

Headphone Amplifier

Digital Core

Serial/Control Port Interface

Ambient Temperature Commercial - CNZ

Automotive - DNZ

VA_HP

1.65

2.37

1.65

2.37

1.65

2.37

1.65

2.37

3.14

-10

-40

1.8

2.5

1.8

2.5

1.8

2.5

1.8

2.5

3.3

1.89

2.63

1.89

2.63

1.89

2.63

1.89

2.63

3.47

+70 +85

V V

V V V

°C °C

ABSOLUTE MAXIMUM RATINGS

(AGND = DGND = 0 V; all voltages with respect to ground.)

Parameters Symbol Min Max Units

DC Power Supply Analog

Digital

Serial/Control Port Interface Input Current (Note 2) Analog Input Voltage Digital Input Voltage

(Note 3)

Ambient Operating Temperature (power applied) Storage Temperature

VA, VA_HP

VD VL

IND

stg

WARNING:Operation at or beyond these limits may result in permanent damage to the device. Normal operation

is not guaranteed at these extremes.

Notes:

1. The device will operate properly over the full range of the analog, headphone amplifier, digital core and serial/control port interface supplies.

2. Any pin except supplies. Transient currents of up to ±100 mA on the analog input pins will not cause SCR latch-up.

3. The maximum over/under voltage is limited by the input current.

-0.3

-±10mA

AGND-0.7 VA+0.7

-0.3 VL+ 0.4 V

-50 +115 °C

-65 +150 °C

3.0

4.0

V V V

12 DS679F1

CS42L51

ANALOG INPUT CHARACTERISTICS (COMMERCIAL - CNZ)

(Test Conditions (unless otherwise specified): Input sine wave (relative to digital full scale): 1 kHz through passive input filter; Measurement Bandwidth is 10 Hz to 20 kHz unless otherwise specified. Sample Frequency = 48 kHz)

VA = 2.5 V (nominal) VA = 1.8 V (nominal)

Parameter (Note 5)

Analog In to ADC (PGA bypassed)

Dynamic Range A-weighted

unweighted

Total Harmonic Distortion + Noise -1 dBFS

-20 dBFS

-60 dBFS

Analog In to PGA to ADC Dynamic Range

PGA Setting: 0 dB A-weighted

unweighted

PGA Setting: +12 dB A-weighted

unweighted Total Harmonic Distortion + Noise PGA Setting: 0 dB -1 dBFS

-60 dBFS PGA Setting: +12 dB -1 dBFS

Analog In to MIC Pre-Amp (+16 dB) to PGA to ADC Dynamic Range

PGA Setting: 0 dB A-weighted

unweighted Total Harmonic Distortion + Noise PGA Setting: 0 dB -1 dBFS

Analog In to MIC Pre-Amp (+32 dB) to PGA to ADC Dynamic Range

PGA Setting: 0 dB A-weighted

unweighted Total Harmonic Distortion + Noise PGA Setting: 0 dB -1 dBFS

Other Characteristics

DC Accuracy Interchannel Gain Mismatch Gain Drift Offset Error SDOUT Code with HPF On Input Interchannel Isolation DAC Isolation (Note 4) Full-scale Input Voltage ADC

PGA (0 dB)

MIC (+16 dB) MIC (+32 dB)

Input Impedance (Note 6) ADC

PGA

MIC

Min Typ Max Min Typ Max Unit

93 90

92 89

85 82

- -85 -79 - -83 -77 dB

--76- --74-dB

--74- --71-dB

-0.2- -0.2-dB

- ±100 - - ±100 - ppm/°C

- 352 - - 352 - LSB

-90--90-dB

-70--70-dB

0.74•VA

0.75•VA

99 96

-86

-76

-36

98 95

91 88

-88

-35

86 83

78 74

0.78•VA

0.794•VA

0.129•VA

0.022•VA 20

39 50

-80

-81

0.82•VA

0.83•VA

90 87

89 86

82 79

0.74•VA

0.75•VA

96 93

-84

-73

-33

95 92

88 85

-86

-32

83 80

75 71

0.78•VA

0.794•VA

0.129•VA

0.022•VA 20

39 50

-78

-80

0.82•VA

0.83•VA

dB dB

dB dB dB

dB dB

Vpp Vpp Vpp Vpp

kΩ kΩ kΩ

DS679F1 13

CS42L51

ANALOG INPUT CHARACTERISTICS (AUTOMOTIVE - DNZ)

(Test Conditions (unless otherwise specified): Input sine wave (relative to full scale): 1 kHz through passive input filter; Measurement Bandwidth is 10 Hz to 20 kHz unless otherwise specified. Sample Frequency = 48 kHz)

VA = 2.5 V (nominal) VA = 1.8 V (nominal)

Parameter (Note 5)

Analog In to ADC

Dynamic Range A-weighted

unweighted

Total Harmonic Distortion + Noise -1 dBFS

-20 dBFS

-60 dBFS

Analog In to PGA to ADC Dynamic Range

PGA Setting: 0 dB A-weighted

unweighted

PGA Setting: +12 dB A-weighted

unweighted Total Harmonic Distortion + Noise PGA Setting: 0 dB -1 dBFS

-60 dBFS PGA Setting: +12 dB -1 dBFS

Analog In to MIC Pre-Amp (+16 dB) to PGA to ADC Dynamic Range

PGA Setting: 0 dB A-weighted

unweighted Total Harmonic Distortion + Noise PGA Setting: 0 dB -1 dBFS

Analog In to MIC Pre-Amp (+32 dB) to PGA to ADC Dynamic Range

PGA Setting: 0 dB A-weighted

unweighted Total Harmonic Distortion + Noise PGA Setting: 0 dB -1 dBFS

Other Characteristics

DC Accuracy Interchannel Gain Mismatch Gain Drift Offset Error SDOUT Code with HPF On Input Interchannel Isolation DAC Isolation (Note 4) Full-scale Input Voltage ADC

PGA (0 dB)

MIC (+16 dB) MIC (+32 dB)

Input Impedance (Note 6) ADC

PGA

MIC

4. Measured with DAC delivering full-scale output power into 16 Ω.

Min Typ Max Min Typ Max Unit

91 78

90 87

83 80

- -85 -77 - -83 -75 dB

--76---74-dB

--74---71-dB

- 0.1 - - 0.1 - dB

- ±100 - - ±100 - ppm/°C

- 352 - - 352 - LSB

-90--90-dB

-70--70-dB

0.74•VA

0.75•VA

18 40 50

99 96

-86

-76

-36

98 95

91 88

-88

-35

86 83

78 74

0.78•VA

0.794•VA

0.129•VA

0.022•VA

-78

-80

0.82•VA

0.83•VA

88 85

87 84

80 77

0.74•VA

0.75•VA

18 40 50

96 93

-84

-73

-33

95 92

88 85

-86

-32

83 80

75 71

0.78•VA

0.794•VA

0.129•VA

0.022•VA

-76

-78

0.82•VA

0.83•VA

dB dB

dB dB dB

dB dB

Vpp Vpp Vpp Vpp

kΩ kΩ kΩ

14 DS679F1

5. Referred to the typical full-scale voltage. Applies to all THD+N and Dynamic Range values in the table.

6. Measured between AINxx and AGND.

ADC DIGITAL FILTER CHARACTERISTICS

Parameter (Note 7) Min Typ Max Unit

Passband (Frequency Response) to -0.1 dB corner Passband Ripple Stopband Stopband Attenuation Total Group Delay

High-Pass Filter Characteristics (48 kHz Fs)

Frequency Response -3.0 dB

-0.13 dB Phase Deviation @ 20 Hz Passband Ripple Filter Settling Time

CS42L51

0 - 0.4948 Fs

-0.09 - 0.17 dB

0.6 - - Fs 33 - - dB

- 7.6/Fs - s

-10-Deg

- - 0.17 dB

-10

3.7

24.2

/Fs 0 s

Hz Hz

7. Response is clock-dependent and will scale with Fs. Note that the response plots (Figure 33 to Figure 41) have been normalized to Fs and can be de-normalized by multiplying the X-axis scale by Fs. HPF parameters are for Fs = 48 kHz.

DS679F1 15

CS42L51

ANALOG OUTPUT CHARACTERISTICS (COMMERCIAL - CNZ)

(Test conditions (unless otherwise specified): Input test signal is a full-scale 997 Hz sine wave; measurement bandwidth is 10 Hz to 20 kHz; Sample Frequency = 48 kHz; test load R

(see Figure 3), and test load R

= 16 Ω, CL = 10 pF (see Figure 3) for the headphone output. HP_GAIN[2:0] = 011.)

= 10 kΩ, CL = 10 pF for the line output

Parameter (Note 8)

RL = 10 kΩ Dynamic Range

18 to 24-Bit A-weighted unweighted 16-Bit A-weighted

unweighted Total Harmonic Distortion + Noise 18 to 24-Bit 0 dB

-20 dB

-60 dB

16-Bit 0 dB

-20 dB

-60 dB

RL = 16 Ω

Dynamic Range 18 to 24-Bit A-weighted

unweighted 16-Bit A-weighted

unweighted Total Harmonic Distortion + Noise 18 to 24-Bit 0 dB

-20 dB

-60 dB

16-Bit 0 dB

-20 dB

-60 dB

Other Characteristics for RL = 16 Ω or 10 k

Output Parameters Modulation Index (MI)

(Note 9) Analog Gain Multiplier (G)

Full-scale Output Voltage (2•G•MI•VA) (Note 9)

Full-scale Output Power (Note 9) Interchannel Isolation (1 kHz) 16 Ω

Interchannel Gain Mismatch Gain Drift AC-Load Resistance (R

Load Capacitance (C

) (Note 10)

Ω

10 kΩ

VA = 2.5V (nominal)

Min Typ Max

92 89

Refer to Table “Line Output Voltage Characteristics” on

Refer to Table “Headphone Output Power Characteristics”

- 0.1 0.25 - 0.1 0.25 dB

- ±100 - - ±100 -

16 - - 16 - - Ω

- - 150 - - 150 pF

98 95 96 93

-86

-75

-35

-86

-73

-33

98 95 96 93

-75

-35

-75

-73

-33

0.6787

0.6047

80 95

-78

-69

page 18

on page 19

VA = 1.8V

(nominal)

Min Typ Max Unit

89 86

95 92 93 90

-88

-72

-32

-88

-70

-30

95 92 93 90

-75

-72

-32

-75

-70

-30

0.6787

0.6047

80 93

-82

-69

dB dB dB dB

dB dB dB dB dB dB

dB dB dB dB

dB dB dB dB dB dB

Vpp

dB dB

ppm/°

16 DS679F1

CS42L51

ANALOG OUTPUT CHARACTERISTICS (AUTOMOTIVE - DNZ)

(Test conditions (unless otherwise specified): Input test signal is a full-scale 997 Hz sine wave; measurement bandwidth is 10 Hz to 20 kHz; Sample Frequency = 48 kHz and 96 kHz; test load R

line output (see Figure 3), and test load R

= 16 Ω, CL = 10 pF (see Figure 3) for the headphone output.

HP_GAIN[2:0] = 011.)

= 10 kΩ, CL = 10 pF for the

Parameter (Note 8)

RL = 10 kΩ Dynamic Range

18 to 24-Bit A-weighted unweighted 16-Bit A-weighted

unweighted Total Harmonic Distortion + Noise 18 to 24-Bit 0 dB

-20 dB

-60 dB

16-Bit 0 dB

-20 dB

-60 dB

RL = 16

Ω

Dynamic Range

18 to 24-Bit A-weighted

unweighted 16-Bit A-weighted

unweighted Total Harmonic Distortion + Noise 18 to 24-Bit 0 dB

-20 dB

-60 dB

16-Bit 0 dB

-20 dB

-60 dB

Other Characteristics for RL = 16 Ω or 10 k

Output Parameters Modulation Index (MI)

(Note 9) Analog Gain Multiplier (G)

Full-scale Output Voltage (2•G•MI•VA) (Note 9)

Full-scale Output Power (Note 9) Interchannel Isolation (1 kHz) 16 Ω

Interchannel Gain Mismatch Gain Drift AC-Load Resistance (R

Load Capacitance (C

) (Note 10)

Ω

10 kΩ

VA = 2.5V (nominal)

Min Typ Max

90 87

Refer to Table “Line Output Voltage Characteristics” on

Refer to Table “Headphone Output Power Characteristics”

- 0.1 0.25 - 0.1 0.25 dB

- ±100 - - ±100 -

16 - - 16 - - Ω

- - 150 - - 150 pF

98 95 96 93

-86

-75

-35

-86

-73

-33

98 95 96 93

-75

-35

-75

-73

-33

0.6787

0.6047

80 95

-73

-67

page 18

on page 19

VA = 1.8V

(nominal)

Min Typ Max Unit

87 84

95 92 93 90

-88

-72

-32

-88

-70

-30

95 92 93 90

-75

-72

-32

-75

-70

-30

0.6787

0.6047

80 93

-80

-67

dB dB dB dB

dB dB dB dB dB dB

dB dB dB dB

dB dB dB dB dB dB

Vpp

dB dB

ppm/°

DS679F1 17

CS42L51

LINE OUTPUT VOLTAGE CHARACTERISTICS

Test conditions (unless otherwise specified): Inp ut test signal is a fu ll-scale 997 Hz sine wave; measurement bandwidth is 10 Hz to 20 kHz; Sample Frequency = 48 kHz; test load R

= 10 kΩ, CL = 10 pF (see Figure 3).

Parameter

AOUTx Voltage Into RL = 10 k

HP_GAIN[2:0]

000 0.3959

001 0.4571

010 0.511 1

011 (default) 0.6047

100 0.7099

101 0.8399

110 1.0000

111 1.1430

Analog

Gain (G)

VA = 2.5V (nominal)

Min Typ Max

VA = 1.8V

(nominal)

Min Typ Max Unit

Ω

VA_HP

1.8 V - 1.34 - - 0.97 - V

2.5 V - 1.34 - - 0.97 - V

1.8 V - 1.55 - - 1.12 - V

2.5 V - 1.55 - - 1.12 - V

1.8 V - 1.73 - - 1.25 - V

2.5 V - 1.73 - - 1.25 - V

1.8 V - 2.05 - 1.41 1.48 1.55 V

2.5 V 1.95 2.05 2.15 - 1.48 - V

1.8 V - 2.41 - - 1.73 - V

2.5 V - 2.41 - - 1.73 - V

1.8 V - 2.85 - 2.05 V

2.5 V - 2.85 - - 2.05 - V

1.8 V - 3.39 - - 2.44 - V

2.5 V - 3.39 - - 2.44 - V

1.8 V

2.5 V - 3.88 - - 2.79 - V

(See (Note 11) 2.79 V

pp pp pp pp pp pp pp pp pp pp pp pp pp pp pp pp

18 DS679F1

CS42L51

HEADPHONE OUTPUT POWER CHARACTERISTICS

Test conditions (unless otherwise specified): Input test signal is a full-scale 997 Hz sine wave; measurement bandwidth is 10 Hz to 20 kHz; Sample Frequency = 48 kHz; test load R

= 16 Ω, CL = 10 pF (see Figure 3).

Parameter

AOUTx Power Into RL = 16

HP_GAIN[2:0]

000 0.3959

001 0.4571

010 0.511 1

011 (default) 0.6 047

100 0.7099

101 0.8399

110 1.0000

111 1.1430

Analog Gain (G)

8. One-half LSB of triangular PDF dither is added to data.

9. Full-scale output voltage and power is determined by the gain setting, G, in register “Headphone Analog

Gain (HP_GAIN[2:0])” on page 57. High gain settings at certain VA and VA_HP supply levels may

cause clipping when the audio signal approaches full-scale, maximum power output, as shown in

Figures 27 - 30 on page 76.

10. See Figure 3. R quired for the internal op-amp's stability and signal integrity. In this circuit topology, C move the band-limiting pole of the amp in the output stage. Increasing this value beyond the recommended 150 pF can cause the internal op-amp to become unstable.

11. VA_HP settings lower than VA reduces the headroom of the h eadphone amplifier. As a resu lt, the DAC may not achieve the full THD+N performance at full-scale output voltage and power.

VA = 2.5V (nominal)

Min Typ Max

VA = 1.8V

(nominal)

Min Typ Max Unit

Ω

VA_HP

1.8 V - 14 - - 7 - mW

2.5 V - 14 - - 7 - mW

1.8 V - 19 - - 10 - mW

2.5 V - 19 - - 10 - mW

1.8 V - 23 - - 12 - mW

2.5 V - 23 - - 12 - mW

1.8 V (Note 11) -17 -mW

2.5 V - 32 - - 17 - mW

1.8 V (Note 11) -23 -mW

2.5 V - 44 - - 23 - mW

1.8 V (Note 9) mW

2.5 V -32 -mW

1.8 V

2.5 V mW

(Note 9, 11)

1.8 V mW

2.5 V mW

and CL reflect the recommended minimum resistance and maximum capacitance re-

will effectively

rms rms rms rms rms rms rms rms rms rms rms rms rms rms rms rms

AOUTx

AGND

51 Ω

0.022 µF

Figure 3. Headphone Output Test Load

DS679F1 19

CS42L51

COMBINED DAC INTERPOLATION & ON-CHIP ANALOG FILTER RESPONSE

Parameter (Note 12) Min Typ Max Unit

Frequency Response 10 Hz to 20 kHz Passband to -0.05 dB corner

to -3 dB corner StopBand StopBand Attenuation (Note 13) Group Delay De-emphasis Error Fs = 32 kHz

Fs = 44.1 kHz

Fs = 48 kHz

-0.01 - +0.08 dB 0

0.5465 - - Fs 50 - - dB

- 10.4/Fs - s

0.4780

0.4996

+1.5/+0

+0.05/-0.25

-0.2/-0.4

Fs Fs

dB dB dB

Notes:

12. Response is clock dependent and will scale with Fs. Note that the response plots (Figure 38 to Figure 41

on page 82) have been normalized to Fs and can be de-normalized by multiplying the X-axis scale by Fs.

13. Measurement Bandwidth is from Stopband to 3 Fs.

SWITCHING SPECIFICATIONS - SERIAL PORT

(Inputs: Logic 0 = DGND, Logic 1 = VL, SDOUT C

LOAD

= 15 pF.)

Parameters Symbol Min Max Units

RESET pin Low Pulse Width (Not e 14 )

MCLK Frequency MCLK Duty Cycle (Note 15)

Slave Mode

Input Sample Rate (LRCK) Quarter-Speed Mode

Half-Speed Mode

Single-Speed Mode

Double-Speed Mode LRCK Duty Cycle SCLK Frequency SCLK Duty Cycle LRCK Setup Time Before SCLK Rising Edge LRCK Edge to SDOUT MSB Output Delay SDOUT Setup Time Before SCLK Rising Edge SDOUT Hold Time After SCLK Rising Edge SDIN Setup Time Before SCLK Rising Edge SDIN Hold Time After SCLK Rising Edge

1/t

s(LK-SK)

d(MSB)

s(SDO-SK)

h(SK-SDO)

s(SD-SK)

1-ms

1.024 38.4 MHz 45 55 %

4 8 4

50 45 55 %

-64•FsHz 45 55 % 40 - ns

-52ns 20 - ns 30 - ns 20 - ns 20 - ns

12.5 25 50

100

kHz kHz kHz kHz

20 DS679F1

Master Mode (Note 17)

CS42L51

Parameters Symbol Min Max Units

Output Sample Rate (LRCK) All Speed Modes

(Note 17)

LRCK Duty Cycle SCLK Frequency SCLK Duty Cycle LRCK Edge to SDOUT MSB Output Delay SDOUT Setup Time Before SCLK Rising Edge SDOUT Hold Time After SCLK Rising Edge SDIN Setup Time Before SCLK Rising Edge SDIN Hold Time After SCLK Rising Edge

14. After powering up the CS42L51, RESET should be held low after the power supplies and clocks are settled.

15. See “Example System Clock Frequencies” on page 79 for typical MCLK frequencies.

16. See

17. “Master” on page 39

18. “MCLK” refers to the external master clock applied.

LRCK

s(LK-SK)

SCLK

SDOUT

SDIN

d(MSB)

s(SD-SK)

MSB

h(SK-SDO)

Figure 4. Serial Audio Interface Slave Mode Timing

1/t

d(MSB)

s(SDO-SK)

h(SK-SDO)

s(SD-SK)

s(SDO-SK)

MSB-1

MCLK

-Hz

----------------128

45 55 %

- 64•F

45 55 %

-52ns 20 - ns 30 - ns 20 - ns 20 - ns

LRCK

SCLK

SDOUT

SDIN

d(MSB)

s(SD-SK)

MSB

h(SK-SDO)

s(SDO-SK)

MSB-1

Figure 5. Serial Audio Interface Master Mode Timing

DS679F1 21

SWITCHING SPECIFICATIONS - I²C® CONTROL PORT

(Inputs: Logic 0 = DGND, Logic 1 = VL, SDA CL=30pF)

Parameter Symbol Min Max Unit

SCL Clock Frequency

RESET Rising Edge to Start

Bus Free Time Between Transmissions Start Condition Hold Time (prior to first clock pulse) Clock Low time Clock High Time Setup Time for Repeated Start Condition SDA Hold Time from SCL Falling (Note 19) SDA Setup time to SCL Rising Rise Time of SCL and SDA Fall Time SCL and SDA Setup Time for Stop Condition Acknowledge Delay from SCL Falling

f t

hdst

low

high

sust

hdd

sud

susp

ack

scl

irs

buf

CS42L51

- 100 kHz

500 - ns

4.7 - µs

4.0 - µs

4.7 - µs

4.0 - µs

4.7 - µs 0-µs

250 - ns

-1µs

- 300 ns

4.7 - µs

300 3450 ns

19. Data must be held for sufficient time to bridge the transition time, t

RST

SDA

SCL

irs

Stop Start

buf

hdst

low

high

hdd

Figure 6. Control Port Timing - I²C

sud

Repeated

Start

sust

hdst

, of SCL.

Stop

susp

22 DS679F1

SWITCHING CHARACTERISTICS - SPI™ CONTROL PORT

(Inputs: Logic 0 = DGN D, Lo gic 1 = VL)

Parameter Symbol Min Max Units

CS42L51

CCLK Clock Frequency

RESET Rising Edge to CS Falling

Falling to CCLK Edge

CS CS

High Time Between Transmissions CCLK Low Time CCLK High Time CDIN to CCLK Rising Setup Time CCLK Rising to DATA Hold Time (Note 20) Rise Time of CCLK and CDIN (Note 21) Fall Time of CCLK and CDIN (Note 21)

20. Data must be held for sufficient time to bridge the transition time of CCLK.

21. For f

<1 MHz.

sck

RST

CCLK

srs

sch

css

scl

dsu

sck

srs

css

csh

scl

sch

dsu

06.0MHz 20 - ns 20 - ns

1.0 - µs 66 - ns 66 - ns 40 - ns 15 - ns

-100ns

csh

CDIN

Figure 7. Control Port Timing - SPI Format

DS679F1 23

DC ELECTRICAL CHARACTERISTICS

(AGND = 0 V; all voltages with respect to ground.)

Parameters Min Typ Max Units

VQ Characteristics

Nominal Voltage Output Impedance DC Current Source/Sink (Note 22)

DAC_FILT+ Nominal Voltage ADC_FILT+ Nominal Voltage

VSS_HP Characteristics

Nominal Voltage DC Current Source

MIC BIAS Characteristics

Nominal Voltage MICBIAS_LVL[1:0] = 00

MICBIAS_LVL[1:0] = 01 MICBIAS_LVL[1:0] = 10

MICBIAS_LVL[1:0] = 11 DC Current Source Power Supply Rejection Ratio (PSRR) 1 kHz

Power Supply Rejection Ratio (PSRR) (Note 23) 1 kHz

CS42L51

-60-dB

0.5•VA 23

VA VA

-0.8•(VA_HP) -

0.8•VA

0.7•VA

0.6•VA

0.5•VA

V kΩ µA

V µA

22. The DC current draw represents the allowed current draw from the VQ pin due to typical leakage through electrolytic de-coupling capacitors.

23. Valid with the recommended capacitor values on DAC_FILT+, ADC_FILT+ and VQ. In crea sing the capacitance will also increase the PSRR.

DIGITAL INTERFACE SPECIFICATIONS & CHARACTERISTICS

Parameters (Note 24) Symbol Min Max Units

Input Leakage Current Input Capacitance

1.8 V - 3.3 V Logic High-Level Output Voltage

Low-Level Output Voltage High-Level Input Voltage

Low-Level Input Voltage

24. See “Digital I/O Pin Characteristics” on page 9 for serial and control port power rails.

(IOH = -100 µA)

(IOL = 100 µA)

-±10µA

-10pF

VL - 0.2 - V

-0.2V

0.68•VL - V

- 0.32•VL V

24 DS679F1

POWER CONSUMPTION

See (Note 25)

CS42L51

Power Ctl. Registers Typical Current (mA)

02h 03h

Operation

PDN_DACB

PDN_DACA

PDN_PGAB

PDN_PGAA

PDN_ADCB

PDN_ADCA

PDN

PDN_MICB

PDN_MICA

Off

(Note 26)

2 Standby (Note 27) 3 Mono Record ADC1111100111

PGA to ADC

MIC to PGA to ADC

(with Bias)

MIC to PGA to ADC

(no Bias)

4 Stereo Record ADC1111000111

PGA to ADC

MIC to PGA to ADC

(no Bias)

5 Mono Playback 1011110111

6 Stereo Playback

Mono Record & Playback

PGA in (no MIC) to Mono Out Phone Monitor

MIC (w/bias) in to Mono Out Stereo Record & Playback

PGA in (no MIC) to Stereo Out

xxxxxxxxxx

xxxxxx1xxx

1110100111

1110100100

1110100101

1100000111

1100000001

0011110111

1010100111

1010100100

0000000111

VA_HP

PDN_MICBIAS

1.8 0 0 0 0 0

2.5 0 0 0 0 0

1.8 0 0.01 0.02 0 0.05

2.5 0 0.01 0.03 0 0.10

1.8 0 1.85 2.03 0.03 7.05

2.5 0 2.07 3.05 0.05 12.94

1.8 0 2.35 2.03 0.03 7.95

2.5 0 2.58 3.08 0.05 14.29

1.8 0 3.67 2.05 0.03 10.36

2.5 0 3.95 3.09 0.05 17.71

1.8 0 3.27 2.03 0.03 9.61

2.5 0 3.52 3.08 0.05 16.62

1.8 0 2.69 2.12 0.03 8.72

2.5 0 2.93 3.18 0.04 15.40

1.8 0 3.65 2.12 0.03 10.45

2.5 0 3.91 3.17 0.04 17.84

1.8 0 5.48 2.11 0.03 13.73

2.5 0 5.76 3.17 0.04 22.45

1.8 1.66 1.40 2.35 0.01 9.74

2.5 2.03 1.71 3.48 0.02 18.08

1.8 2.77 2.05 2.35 0.01 12.93

2.5 3.21 2.50 3.49 0.02 23.02

1.8 1.66 3.63 2.73 0.03 14.49

2.5 2.03 4.16 4.08 0.05 25.79

1.8 1.66 4.95 2.75 0.03 16.90

2.5 2.03 5.52 4.08 0.05 29.20

1.8 2.77 5.59 2.82 0.03 20.18

2.5 3.21 6.28 4.19 0.04 34.30

(Note 28)

Total

Power

(mW

rms

)

25. Unless otherwise noted, test conditions are as follows: All zeros input, slave mode, sample rate = 48 kHz; No load. Digital (VD) and logic (VL) supply current will vary depending on speed mode and master/slave operation.

26. RESET

27. RESET

pin 25 held LO, all clocks and data lines are held LO. pin 25 held HI, all clocks and data lines are held HI.

28. VL current will slightly increase in master mode.

DS679F1 25

4. APPLICATIONS

4.1 Overview

4.1.1 Architecture

The CS42L51 is a highly integrated, low power, 24-bit au dio CODEC comprised of stereo analog-to-digital converters (ADC), and stereo digital-to-analog converters (DAC) designed using multi-bit delta-sigma techniques. The DAC operates at an oversampling ratio of 128Fs and the ADC operates at 64Fs, where Fs is equal to the system sample rate. The different clock rates ma ximize power savings while maintaining high performance. The CODEC operates in one of four sample rate speed modes: Quarter, Half, Single and Double. It accepts and is capable of generating serial port clocks (SCLK, LRCK) derived from an input Master Clock (MCLK).

4.1.2 Line & MIC Inputs

The analog input portion of the CODEC allows selection from and configuration of multiple combinations of stereo and microphone (MIC) sources. Six line inputs with configuration for two MIC inputs (or one MIC input with common mode rejection), two MIC bias outputs and independent channel control (including a high-pass filter disable function) are available. A Programmable Gain Amplifier (PGA), MIC boost, and Automatic Level Control (ALC), with noise gate settings, provide analog gain and adjustment. Digital volume controls, including gain, boost, attenuation and inversion are also available.

CS42L51

4.1.3 Line & Headphone Outputs

The analog output portion of the D/A includes a headphone amplifier capable of driving headphone and line-level loads. An on-chip charge pump creates a negative headphone supply allowing a full-scale output swing centered around ground. This eliminates the need for large DC-Blocking capacitors and allows the amplifier to deliver more power to headphone loads at lower supply voltages. Eight gain settings for the headphone amplifier are available.

4.1.4 Signal Processing Eng ine

A signal processing engine is available to process serial input D/A data be fore output to the DAC. The D/A data has independent volume controls and mixing functions such as mo no mixes a nd left/right cha nnel swaps. A Tone Control provides bass and treble at four selectable corner frequencies. An automatic level control provides limiting capabilities at programmable attack and release rates, maximum thresholds and soft ramping. A 15/50 µs de-emphasis filter is also available at a 44.1 kHz sample rate.

4.1.5 Beep Generator

A beep may be generated internally at select frequencies across approximately two octave major scales and configured to occur continuously, periodically or at single time interva ls controlled by the user. Volume may be controlled independently.

4.1.6 Device Control (Hardware or Software Mode)

In Software Mode, all functions and features may be controlled via a two-wire I²C or three-wire SPI control port interface. In Hardware Mode, a limited feature set may be controlled via stand-alone control pins.

4.1.7 Power Management

Two Software Mode control registers provide independent power-down control of the ADC, DAC, PGA, MIC pre-amp and MIC bias, allowing operation in select applications with minimal power consumption.

26 DS679F1

4.2 Hardware Mode

A limited feature-set is available when the CODEC powers up in Hardware Mode (see “Recommended Pow-

er-Up Sequence” on page 41) and may be controlled via stand-alone control pins. Table 2 shows a list of

functions/features, the default configuration and the associated stand-alone control available.

Hardware Mode Feature/Function Summary

Feature/Function Default Configuration Stand-Alone Control Note

Power Control CODEC

PGAx ADCx DACx

MIC Bias

MICx Pre-amplifier Auto-Detect Speed Mode Serial Port Slave

Serial Port Master

MCLK Divide

Serial Port Master / Slave Selection Interface Control ADC

DAC

ADC Volume & Gain Digital Boost

Soft Ramp

Zero Cross

Invert

PGAx

Attenuator

ALC

Noise Gate

ADCx High-Pass Filter ADCx High-Pass Filter Freeze

Line/MIC Input Select DAC Volume & Gain HP Gain

AOUTx Volume

Invert

Soft Ramp

Zero Cross DAC De-Emphasis Signal Processing Engine (SPE) Mix

Beep

Tone Control

Peak Detect and Limiter Data Selection Channel Mix ADC

DAC

Charge Pump Frequency

Table 2. Hardware Mode Feature Summary

CS42L51

Powered Up Powered Up Powered Up

Powered Up Powered Down Powered Down

Enabled - -

Auto-Detect Speed Mode

Single-Speed Mode

(Selectable) “MCLKDIV2” pin 2

(Selectable) “M/S” pin 29

(Selectable) “I²S/LJ” pin 3

Disabled Disabled Disabled Disabled

0 dB

0 dB Disabled Disabled

Enabled

Continuous DC Subtraction

AIN1A to PGAA AIN1B to PGAB

G = 0.6047

0 dB Disabled Enabled Disabled

(Selectable) “DEM” pin 4

Disabled Disabled Disabled Disabled

Data Input (PCM) to DAC - -

ADCA = L; ADCB = R

PCMA = L; PCMB = R

(64xFs)/7 - -

-see Section

4.5 on page 38

see Section

4.5 on page 38

see Section

4.6 on page 40

see Section

on page 34

DS679F1 27

4.3 Analog Inputs

AINxA and AINxB are the analog inputs, internally biased to VQ, that accepts line-level and MIC-level signals, allowing various gain and signal adjustments for each channel.

CS42L51

ADCA_MUTE

+20dB Digital

Boost

ADCA_ATT[7:0]

0/-96dB

1dB steps

Attenuator

SOFTA

MUX

DIGMIX

MUX

MICMIX

ADCA_HPF FREEZE ADCA_HPF ENABLE

ALC_ARATE[5:0] ALC_RRATE[5:0]

ALCA_SRDIS ALCA_ZCDIS

ALC_ENA

MAX[2:0]

MIN[2:0]

ALC_ENB ALCB_SRDIS ALCB_ZCDIS

ADCA_DBOOST

ALC

PCM Serial Interface

MUX

ADCB_HPF FREEZE ADCB_HPF ENABLE

ADCB_DBOOST

TO SIGNAL PROCESSING ENGINE (SPE)

FROM SIGNAL PROCESSING ENGINE (SPE)

+20dB Digital

Boost

SOFTB

Attenuator

ADCB_MUTE

ADCB_ATT[7:0]

0/-96dB

1dB steps

Figure 8. Analog Input Architecture

4.3.1 Digital Code, Offset & DC Measurement

Noise Gate

PDN_ADCA

Multibit

Oversampling

ADC

INV_ADCA

NG_ALL NG_EN THRESH[3:0] NGDELAY[1:0]

PDN_ADCB

Multibit

Oversampling

ADC

INV_ADCB

PGAA_VOL[5:0] ADC_SNGVOL SOFTA ZCROSSA

+12/-3dB

0.5dB steps

PGA

PDN_PGAA

AINA_MUX[1:0]

MICBIAS_LVL[1:0]

PDN_MICBIAS

PGAB_VOL[5:0] ADC_SNGVOL SOFTB ZCROSSB

+12/-3dB

0.5dB steps

PGA

PDN_PGAB

AINB_MUX[1:0]

MUX

+16/ 32 dB

MICA_BOOST

PDN_MICA

MICBIAS

MICBIAS_SEL

+16/

32dB

MICB_BOOST

PDN_MICB

AIN1A AIN2A

AIN3A/ MICIN1

AIN1B AIN2B/MICBIAS

AIN3B/ MICIN2/ MICBIAS

The ADC output data is in two’s complement binary format. For inputs above positive full scale or below negative full scale, the ADC will output 7FFFFFH or 800000H, respectively and cause the ADC overflow bit to be set to a ‘1’.

Given the two’s complement format, low-level signals may cause the MSB of the se rial data to periodically toggle between ‘1’ and ‘0’, poss ibly int roducing noise in to the sys tem as the bit switches back an d fort h. To prevent this phenomena, a constant DC offset is a dded to th e ser ial d ata brin ging th e low- level sig nal just above the point at which the MSB would normally toggle, thus reducing the noise introduced. Note that this offset is not removed (refer to “Analog Input Characteristics (Commercial - CNZ)” on page 13 and/or “Analog Input Characteristics (Automotive - DNZ)” on page 14 for the specified offset level).

The CODEC may be used to measure DC voltages by disabling the high-pass filter for the designated channel. DC levels are measured relative to VQ and will be decoded as positive two’s complement binary numbers above VQ and negative two’s complement binary numbers below VQ.

Software Controls:

“Status (Address 20h) (Read Only)” on page 73, “ADC Control (Address 06h)” on page 54.

28 DS679F1

4.3.2 High-Pass Filter and DC Offset Calibration

The high-pass filter continuously subtracts a measure of the DC offset from the output of the decimation filter. If the high-pass filter is “frozen” during normal operation, the current value of the DC offset for the corresponding channel is held. It is this DC offset that will continue to be subtracted from the conversion result. This feature makes it possible to perform a system DC offset calibration by:

1. Running the CODECwith the high-pass filter enabled and the DC offset not “frozen” until the filter settles. See the Digital Filter Characteristics for filter settling time.

2. Freezing the DC offset.

The high-pass filters are controlled using the ADCx_HPFRZ and ADCx_HPFEN bits. If a particular ADC channel is used to measure DC voltages, the high-pass filter may be disabled using

the ADCx_HPFEN bit.

CS42L51

Software Controls:

“ADC Control (Address 06h)” on page 54.

4.3.3 Digital Routing

The digital output of the ADC may be internally routed to the signal processing engi ne (SPE) for playba ck of analog input signals. Volume to the DAC may be controlled using the ADCMIX[6:0] bits. The serial input data may also be routed to the ADC serial interface using the DIGMIX bit. This is useful for recording a digital mix along with the analog input.

Software Controls:

“ADCx Mixer Volume Control: ADCA (Address 0Eh) & ADCB (Address 0Fh)” on page 61, “Inter- face Control (Address 04h)” on page 52.

4.3.4 Differential Inputs

The stereo pair inputs act as a single differential input when the MICMIX bit is enabled. This p rovides common mode rejection of noise in digitally intense PCB’s where the microphone signal traverses long traces, or across long microphone cables as illustrated in Figure 9.

Since the mixer provides a differential combination of the two signals, the potential input mix may exceed the maximum full-scale input and result in clipping. The level out of the mixer, therefore, is automatically attenuated 6 dB. Gain may be applied using either the analog PGA o r MIC Pre-amp or the digital ADCMIX volume control to re-adjust a small signal to desired levels.

The analog inputs may also be used as a differential input pair as illustrated in Figure 10. The two channels are differentially combined when the MICMIX bit is enabled.

4.3.4.1 External Passive Components

The microphone input is internally biased to VQ. Input signals must be AC coupled using external capacitors with values consistent with the desired high-pass filter design. The MICINx input resistance of 50 kΩ may be combined with an external capacitor of 1 µF to achieve the cutoff frequency defined by the equation,

An electrolytic capacitor must be placed such that the positive terminal is positioned relative to the side with the greater bias voltage. The MICBIAS voltage level is controlled by the MICBIAS_LVL[1:0] bits.

DS679F1 29

CS42L51

----------------------------------------------- 3.18 H z==

2π 50 k Ω()1 µF()

The MICBIAS series resistor must be selected based on the requirements of the particular microphone used. The MICBIAS output pin is selected using the MICBIAS_SEL bit.

Software Controls:

“Interface Control (Address 04h)” on page 52, “MIC Control (Address 05h)” on page 53.

MICBIAS

MICIN1

MICIN2

Figure 9. MIC Input Mix w/Common Mode Rejection

2.5 V

2.15 V

1.25 V

0.35 V

2.15 V

1.25 V

0.35 V

Full-Scale Differential Input Level (MICMIX=1)

= (AINxA - AINxB) = 3.6 V

Figure 10. Differential Input

= 1.27 V

AINxA

AINxB

RMS

30 DS679F1

4.3.5 Analog Input Multiplexer

A stereo 4-to-1 analog input multiplexer selects between a line-level input source, or a mic-level input source, depending on the PDN_PGAx and AINx_MUX[1:0] bit settings. Signals may be routed to or bypassed around the PGA. To conserve power, the PGA’s may be powered down allowing the u ser to select from multiple line-level sources and route the stereo signal directly to the ADC. When using the MIC preamp, however, the PGA must be powered up.

Analog input channel B may also be used as an output for the MIC bias voltage. The MICBIAS_SEL bit routes the bias voltage to either of two pins. The multiplexer must then select from the remainder of the two input channels.

The ADC, PGA and MIC pre-amplifier each has an associated input resistance. When selecting between these paths, the input resistance to the CODEC will change accordingly. Refer to the input resistance characteristics in the Characteristic and Specification Tables for the input resistance of each path.

CS42L51

Software Controls:

“Power Control 1 (Address 02h)” on page 49, “MIC Control (Ad dress 05h)” on page 53 “ADCx Input Select, Invert & Mute (Address 07h)” on page 56.

4.3.6 MIC & PGA Gain

The MIC-level input passes through a +16 dB or +32 dB analog gain stage prior to the input multiplexer, allowing it to be used for microphone level signals without the need for any e x terna l ga in. The PGA mu st be powered up when using the MIC pre-amp.

The PGA stage provides an additional +12 dB to -3 dB of analog gain in 0.5 dB steps.

Software Controls:

“Power Control 1 (Address 02h)” on page 49, “ADCx Input Select, Invert & Mute (Address 07h)” on page 56, “ALCX & PGAX Control: ALCA, PGAA (Address 0Ah) & ALCB, PGAB (Address 0Bh)” on page 59, “MIC Control (Address 05h)” on page 53.

DS679F1 31

4.3.7 Automatic Level Control (ALC)

When enabled, the ALC monitors the analog input signal after the digital attenuator, detects when peak levels exceed the maximum threshold settings and lowers , first, the PGA gain settings and then increases the digital attenuation levels at a programmable attack rate and maintains the resulting level below the maximum threshold.

When input signal levels fall below the minimum threshold, digital attenuation levels are decreased first and the PGA gain is then increased at a programmable release rate and maintains the resulting level above the minimum threshold.

Attack and release rates are affected by the ADC soft ramp/zero cross settings and sample rate, Fs. ALC soft ramp and zero cross dependency may be independently enabled/disabled.

Recommended settings: Best level control may be realized with the fastest attack and slowest release setting with soft ramp enabled in the control registers. in the PGAx_VOL register. The ALC will only apply the gain set in the PGAx_VOL. the output signal between the MIN and MAX thresholds. As the input signal level changes, the level-controlled output may not always be the same but will always fall within the thresholds.

CS42L51

Note: 1.) The maximum realized gain must be set

2.) The ALC maintains

Software Controls:

MIN[2:0]

below full scale

(after ALC)

MIN[2:0]

below full scale

Input

ALC

Output

“ALC Enable & Attack Rate (Address 1Ch)” on page 70, “ALC Release Rate (Address 1Dh)” on page 71, “ALC Threshold (Address 1Eh)” on page 71, “ALCX & PGAX Control: ALCA, PGAA (Address 0Ah) & ALCB, PGAB (Address 0Bh)” on page 59.

MAX[2:0]

below full scale

ADCx_ATT[7:0] and

PGA Gain and/or Attenuator

RRATE[5:0]

ARATE[5:0]

PGAx_VOL[4:0] volume controls should NOT be adjusted manually when

ALCx is enabled.

MAX[2:0]

below full scale

Figure 11. ALC

32 DS679F1

4.3.8 Noise Gate

The noise gate may be used to mute signal levels that fall below a programmable thre shold. This prevents the ALC from applying gain to noise. A programma ble delay may be used to set the minimum time before the noise gate attacks the signal.

Maximum noise gate attenuation levels will depend on the gain applied in either the PGA or MIC pre-amplifier. For example: If both +32 dB pre-amplification and +12 dB programmable gain is applied, the maximum attenuation that the noise gate achieves will be 52 dB (-96 + 32 + 12) below full-scale.

Ramp-down time to the maximum setting is affected by the SOFTx bit. Recommended settings: For best results, enable soft ramp for the digital attenuator. When the analog in-

puts are configured for differential signals (see “Differential Inputs” on page 29), enable the NG_ALL bit to trigger the noise gate only when both inputs fall below the threshold.

CS42L51

Software Controls:

“Noise Gate Configuration & Misc. (Address 1Fh)” on page 72, “ADC Control (Address 06h)” on page 54.

Output

(dB)

-52 dB

-96 -40 THRESH[2:0]

-64 dB

-80 dB

Maximum Attenuation*

Input (dB)

Figure 12. Noise Gate Attenuation

DS679F1 33

4.4 Analog Outputs

AOUTA and AOUTB are the ground-centered line or headpho ne outputs. Various signal processing options are available, including digital mixes with the ADC si gnal and an interna l Beep Generator . The desire d path to the DAC must be selected using the DATA_SEL[1:0] bits.

CS42L51

PCM Serial Interface

Software Controls:

DEEMPH

“DAC Control (Address 09h)” on page 58.

SIGNAL PROCESSING ENGINE (SPE)

OUTA_VOL[7:0] OUTB_VOL[7:0]

+12dB/-102dB

0.5dB steps

MUTE_PCMMIXA

MUTE_PCMMIXB PCMMIXA_VOL[6:0] PCMMIXB_VOL[6:0]

+12dB/-51.5dB

0.5dB steps

Demph

OFFTIME[2:0]

ONTIME[3:0]

FREQ[3:0]

REPEAT

VOL

BEEP

PCMA[1:0] PCMB[1:0]

Channel

Swap

2.0dB steps

Beep

Generator

BPVOL[4:0]

0dB/-50dB

VOL

Chnl Vol.

Settings

DAC_SZC[1:0]

DACA_MUTE DACB_MUTE

INV_DACA INV_DACB

DAC_SNGVOL

AMUTE

VOL

TC_EN

Bass/

Treble/

Control

BASS_CF[1:0] TREB_CF[1:0]

BASS[3:0] TREB[3:0]

+12.0dB/-10.5dB

1.5dB steps

ARATE[7:0] RRATE[7:0] MAX[2:0] MIN[2:0] LIM_SRDIS LIM_ZCDIS LIMIT_EN

Limiter

Detect

Peak

DATA_SEL[1:0]

PDN_DACA PDN_DACB

Switched

Capacitor DAC

and Filter

Headphone Amp - GND

Centered

CHRG_FREQ[3:0]

HP_GAIN[2:0]

Charge

Pump

Left/Right HP Out

4.4.1 De-Emphasis Filter

The CODEC includes on-chip digital de-emphasis optimized for a sample rate of 44.1 kHz. The filter response is shown in Figure 14. The de-emphasis feature is included to accommodate audio recordings that utilize 50/15 µs pre-emphasis equalization as a means of noise reduction. De-emphasis is only available in Single-Speed Mode.

Software Controls:

Hardware Control:

“DAC Control (Address 09h)” on page 58.

“DEM” pin 4.

Figure 13. Output Architecture

Setting Selection

LO HI

No De-Emphasis

De-Emphasis Applied

34 DS679F1

Gain

0dB

CS42L51

T1=50 µs

-10dB

4.4.2 Volume Controls

Three digital volume control functions are implemented, offering independent control over the ADC and PCM signal paths into the mixer as well as a combined control over the mixed signals. All volume controls are programmable to ramp in increments o f 0.125 dB at a rate controlled by the DAC soft ramp/zero cross settings.

All signal paths may also be independently muted via mute control bits. When enabled, each bit attenuates the signal to its maximum value. When the mute bit is disabled, the signal returns to the attenuation level set in the respective volume control register. The attenuation is ramped up and down at the rate specified by the DAC_SZC[1:0] bits.

“ADCx Mixer Volume Control: ADCA (Address 0Eh) & ADCB (Address 0Fh)” on page 61, “PCMX

Software Controls:

Mixer Volume Control: PCMA (Address 10h) & PCMB (Address 11h)” on page 62, “AOUTx Vol-

ume Control: AOUTA (Address 16h) & AOUTB (Address 17h)” on page 66, “DAC Output Control

(Address 08h)” on page 57.

4.4.3 Mono Channel Mixer

A channel mixer may be used to create a mix of the left and right channels for either the PCM or ADC signals. This mix allows the user to produce a MONO signal from a stereo source. The mixer may also be used to implement a left/right channel swap.

T2 = 15 µs

F1 F2

3.183 kHz 10.61 kHz

Figure 14. De-Emphasis Curve

Frequency

Software Controls:

“PCM Channel Mixer (Address 18h)” on page 67.

4.4.4 Beep Generato r

The Beep Generator generates audio frequencies across approximately two octave major sca les. It offers three modes of operation: Continuous, multiple and single (one-shot) beeps. Sixteen on and eight off times are available.

Note: The Beep is generated before the limiter and ma y affe ct desire d limitin g perfo rmance. If th e limiter

function is used, it may be required to set the Beep volume sufficiently below the threshold to prevent the peak detect from triggering. Since the master volume control, AOUTx_VOL[7:0], will affect the Beep volume, DAC volume may alternatively be controlled using the PCMMIXx_VOL[6:0] bits.

Software Controls:

“Beep Frequency & Timing Configuration (Address 12h)” on page 62, “Beep Off Time & Volume

(Address 13h)” on page 63, “Beep Configuration & Tone Configuration (Address 14h)” on page 64

DS679F1 35

CS42L51

REPEAT = '1' BEEP = '1'

REPEAT = '1' BEEP = '0'

REPEAT = '0' BEEP = '1'

BPVOL[4:0]

FREQ[3:0]

4.4.5 Tone Control

Shelving filters are used to implement bass and treble (boost and cut) with four selectable corner frequencies. Boosting will affect peak detect and limiting when levels exceed the maximum threshold settings.

Software Controls:

CONTINUOUS BEEP: Beep turns on at a configurable frequency (FREQ) and volume (BPVOL) and remains on until REPEAT is cleared.

MULTI-BEEP: Beep turns on at a configurable frequency (FREQ) and volume (BPVOL) for the duration of ONTIME and turns off for the duration of OFFTIME. On and off cycles are repeated until REPEAT is cleared.

SINGLE-BEEP: Beep turns on at a configurable frequency (FREQ) and volume (BPVOL) for the duration of ONTIME. BEEP must be cleared and set for additional beeps.

ONTIME[3:0] OFFTIME[2:0]

Figure 15. Beep Configuration Options

“Tone Control (Address 15h)” on page 65.

...

4.4.6 Limiter

When enabled, the limiter monitors the digital input signal before th e DAC modulator, detects when leve ls exceed the maximum threshold settings and lowers the AOUT volume at a programmable attack rate below the maximum threshold. When the input signal level falls below the maximum threshold, the AOUT volume returns to its original level set in the Volume Control register at a programmable release rate. Attack and release rates are affected by the DAC soft ramp/zero cross settings and sample rate, Fs. Limiter soft ramp and zero cross dependency may be independently enabled/disabled.

Recommended settings: Best limiting performance may be realized with the fastest attack and slowest release setting with soft ramp enabled in th e control registe rs. The “cushio n” bits allow the user to set a threshold slightly below the maximum threshold for hysteresis control - this cushions the sound as the limiter attacks and releases.

Note:

1. When the Limiter is enab led, the AOUT Volume is automatically controlled and should not be adjusted manually. Alternative volume control may be realized using the PCMMIXx_VOL[6:0] bits.

2. The Limiter maintains the output signal between the CUSH and MAX thresholds. As the digita l input signal level changes, the level-controlled output may not always be the same but will always fall within the thresholds.

Software Controls:

“Limiter Release Rate Register (Address 1Ah)” on page 69, “Limiter Attack Rate Register (Address 1Bh)” on page 70, “DAC Control (Address 09h)” on page 58

36 DS679F1

Input

MAX[2:0]

Limiter

Output

(after Limiter)

MAX[2:0]

Volume

ATTACK/RELEASE SOUND

CUSHION

CS42L51

AOUTx_VOL[7:0] volume

control should NOT be

adjusted manually when

Limiter is enabled.

CUSH[2:0]

Figure 16. Peak Detect & Limiter

4.4.7 Line-Level Outputs and Filtering

The CODEC contains on-chip buffer amplifiers capable of producing line level sing le-ended outputs on AOUTA and AOUTB. These amplifiers are ground centere d and do not have any DC of fset. A load stabilizer circuit, shown in the “Typical Connection Diagram (Software Mode)” on page 10 and the “Typical

Connection Diagram (Hardware Mode)” on page 11, is required on the analog outputs. This allows the

DAC amplifiers to drive line or headphone outputs. Also shown in the Typical Connection diagrams is the r ecommended passive output filter to support high-

er impedances such as those found on the inputs to operational amplifiers. “Rext”, shown in the typical connection diagrams, is the input impedanc e of the re ce ivin g de vice .

The invert and digital gain controls may be used to provide phase and/or amplitude compensation for an external filter.

The delta-sigma conversion process produces high fr equency noise beyond the audio passband, most of which is removed by the on-chip analog filters. The remaining out-of-band noise can be attenu ated using an off-chip low pass filter.

Software Controls:

“DAC Output Control (Address 08h)” on page 57, “AOUTx Volume Control: AOUTA (Address 16h) & AOUTB (Address 17h)” on page 66.

RRATE[5:0]ARATE[5:0]

DS679F1 37

4.4.8 On-Chip Charge Pump

An on-chip charge pump derives a negative supply voltage from the VA_HP supply. This provides dual rail supplies allowing a full-scale output swing centered around ground and eliminates the need for large, DC-blocking capacitors. Added benefits include greater pop suppression and improved low frequency (bass) response. drop on the VA_HP supply will directly impact the derived negative voltage on the charge pump supply, VSS_HP, and may result in clipping.

The FLYN and FLYP pins connect to internal switches that char ges and discharges the externa l capacitor attached, at a default switching frequency. This frequency may be adjusted in the control port registers. Increasing the charge-pumping capacitor will slightly decease the pumping frequency. The capacitor connected to VSS_HP acts as a charge reservoir for the negative supply as well as a filter for the ripple induced by the charge pump. Increasing this capacitor will decrease the ripple on VSS_HP. Refer to the typical connection diagrams in Figure 1 on page 10 or Figure 2 on page 11 for the recommended capacitor values for the charge pump circuitry.

Note: Series resistance in the path of the power supplies must be avoided. Any voltage

CS42L51

Software Controls:

4.5 Serial Port Clocking

The CODEC serial audio interface port operates either as a slave or master. It accepts externally generated clocks in slave mode and will generate synchronous clocks derived from an input master clock (MCLK) in master mode.

The frequency of the MCLK must be an integer multiple of, and synchronous with, the system sample rate, Fs. The LRCK frequency is equal to Fs, the frequency at which audi o samples for each cha nnel are clocked into or out of the device.

The SPEED and MCLKDIV2 software control bits or the SDOUT/(M/S pins, configure the device to generate the proper clocks in Master Mode and receive the proper clocks in Slave Mode. The value on the SDOUT pin is latched immediately after powering up in Hardware Mode.

Software

Control:

Hardware

Control:

“Charge Pump Frequency (Address 21h)” on page 74.

) and MCLKDIV2 stand-alone control

“MIC Power Control & Speed Control (Address 03h)” on page 50, “DAC Control (Address 09h)” on page 58.

Pin Setting Selection

“SDOUT, M/S” pin 29

“MCLKDIV2” pin 2

47 kΩ Pull-down

47 kΩ Pull-up

Slave Master No Divide MCLK is divided by 2 prior

to all internal circuitry.

38 DS679F1

4.5.1 Slave

LRCK and SCLK are inputs in Slave Mode. The speed of the CODEC is automatically determined based on the input MCLK/LRCK ratio when the Auto-Detect function is enabled. Certain input clock ratios will then require an internal divide-by-two of MCLK* using either the MCLKDIV2 bit or the MCLKDIV2 standalone control pin.

Additional clock ratios are allowed when the Auto-Detect function is disabled; but the appropriate speed mode must be selected using the SPEED[1:0] bits.

Auto-Detect QSM HSM SSM DSM

Disabled

(Software

Mode only)

Enabled

*MCLKDIV2 must be enabled.

4.5.2 Master

LRCK and SCLK are internally derived from the internal MCLK (after the divide, if MCLKDIV2 is enabled). In Hardware Mode the CODEC operates in single-speed only. In Software Mode, the CODEC operates in either quarter-, half-, single- or double-speed depending on the setting of the SPEED[1:0] bits.

512, 768, 1024, 1536,

2048, 3072

1024, 1536, 2048*,

3072*

CS42L51

256, 384, 512, 768,

1024, 1536

512, 768, 1024*, 1536* 256, 384, 512*, 768* 128, 192, 256*, 384*

Table 3. MCLK/LRCK Ratios

128, 192, 256, 384,

512, 768

128, 192, 256, 384

MCLK

÷ 1

÷ 2

MCLKDIV2

Figure 17. Master Mode Timing

÷ 128

÷ 256

÷ 512

÷ 2

÷ 4

÷ 8

Double

Speed

Single

Speed

Half

Speed

Quarter

Speed

Double Speed

Single Speed

Half

Speed

Quarter

Speed

SPEED[1:0]

LRCK Output (Equal to Fs)

SCLK Output

DS679F1 39

4.5.3 High-Impedance Digital Output

The serial port may be placed on a clock/data bus that allows multiple masters for the serial port I/O without the need for external buffers. The 3ST_SP bit places the in ternal buffers for these I/O in a high-impedance state, allowing another device to transmit serial port data without bus contention.

CS42L51

Transmitting Device #1

3ST_SP

Figure 18. Tri-State Serial Port

4.5.4 Quarter- and Half-Speed Mode

Quarter-Speed Mode (QSM) and Half-Speed Mode (HSM) allow lower sample rates while maintaining a relatively flat noise floor in the typical audio band of 20 Hz - 20 kHz. Single-Speed Mode (SSM) will allow lower frequency sample rates; however, the DAC's noise floor, that normally rises out-of-band, will scale with the lower sample rate and begin to rise within the audio band. QSM and HSM corrects for most of this scaling, effectively increasing the dynamic range of the CODEC at lower sample rates, relative to SSM.

4.6 Digital Interface Formats

Transmitting Device #2

SDOUT

SCLK/LRCK

Receiving Device

The serial port operates in standard I²S, Left-Ju stified or Rig ht-Justified (DAC only) digital interface formats with varying bit depths from 16 to 24. Data is clocked out of the ADC or into the DAC on the rising edge of SCLK. Figures 19-21 illustrate the general structure of each format. Refer to “Switching Specifications - Se-

rial Port” on page 20 for exact timing relationship between clocks and data.

Software

Control:

“Interface Control (Address 04h)” on page 52.

Pin Setting Selection

Hardware

Control:

“I²S/LJ” pin 3

Left-Justified Interface I²S Interface

LRCK SCLK

SDIN

MSB LSB

40 DS679F1

Left Channel Right Channel

MSB

AOUTA / AINxA

Figure 19. I²S Format

AOUTB / AINxB

LSB

MSB

CS42L51

LRCK SCLK

SDIN

LRCK SCLK

SDIN

MSB LSB

4.7 Initialization

The initialization and Power-Down sequence flowchart is shown in Figure 22 on page 42. The CODEC enters a Power-Down state upon initial power-up. The inter polation and decima tion filters, de lta-sigma mo dulators and control port registers are reset. The internal voltage reference, multi-bit DAC and ADC and switched-capacitor low-pass filters are powered down.

The device will remain in the Power-Down state until the RESET cessible once RESET in “Softwar e Mode” on page 43. If a valid write sequence to the control port is not made within appro ximately 10 ms, the CODEC will enter Hardware Mode.

Left Channel Right Channel

MSB

AOUTA / AINxA

Figure 20. Left-Justified Format

Left Channel Right Chan nel

MSB LS B

AOUTA

Figure 21. Right-Justified Format (DAC only)

AOUTB / AINxB

AOUTB

MSB

LSB

pin is brought high. The control port is ac-

is high and the desired register settings can be loaded per the interface descrip tions

MSB

LSB

Once MCLK is valid, the quiescent voltage, VQ, and the internal voltage references, DAC_FILT+ and ADC_FILT+ will begin powering up to normal operation. The charge pump slowly powers up and charges the capacitors. Power is then applied to the headphone amplifiers and switched-capacitor filters, and the analog/digital outputs enter a muted state. Once LRCK is valid, MCLK occurrences are counted over one LRCK period t o d etermine th e M CLK/LRCK fr equency ratio and normal operation begins.

4.8 Recommended Power-Up Sequence

1. Hold RESET low until the power supplies are stable.

2. Bring RESET

3. For Software Mode operation, set the PDN bit to ‘1’b in under 10 ms. This will place the device in “standby”.

4. Load the desired register settings while keeping the PDN bit set to ‘1’b.

5. Start MCLK to the appropriate frequency, as discussed in Section 4.5.

6. Set the PDN bit to ‘0’b.

7. Apply LRCK,SCLK and SDIN for normal operation to begin.

8. Bring RESET prevent power glitch related issues.

high. After approximately 10 ms, the device will enter Hard wa re Mod e .

low if the analog or digital supplies drop below the recommended operating condition to

DS679F1 41

4.9 Recommended Power-Down Sequence

To minimize audible pops when turning off or placing the CODEC in standby,

1. Mute the DAC’s and ADC’s.

2. Set the PDN bit in the power control register to ‘1’b. The CODEC will not power down until it reaches a fully muted sate. Do not remove MCLK until after the part has fully muted. Note that it may be necessary to disable the soft ramp and/or zero cross volume transitions to achieve faster muting/power down.

3. Bring RESET

low.

No Power

1. No audio signal generated.

CS42L51

Power Off Transition

1. Audible pops.

Reset Transition

1. Pops suppressed.

ERROR: Power removed

Off Mode (Power Applied)

1. No audio signal generated.

2. Control Port Registers reset to default.

RESET = Low?

Control Port

Control Port Valid

Write Seq. within

Hardware Mode

Minimal feature

set support.

Yes

Active

Yes

10 ms?

Software Mode

Registers setup to

desired settings.

ERROR: MCLK/LRCK ratio change

RESET = Low

PDN bit = '1'b?

MCLK Applied?

20 ms delay

Charge Caps

1. VQ Charged to quiescent voltage.

2. Filtx+ Charged.

ADC Initialization

2048 internal

MCLK cycle delay

Digital/Analog

Output Muted

Sub-Clocks Applied

1. LRCK valid.

2. SCLK valid.

3. Audio samples processed.

MCLK/LRCK

Ratio?

Audio signal generated per control port or stand-

Normal Operation

alone settings.

Yes

Valid

Yes

DAC Initialization

50 ms delay

Charge Pump

Powered Up

20 µs delay

Headphone Amp

Powered Up

PDN bit set to '1'b (software mode only)

Standby Mode

1. No audio signal generated.

2. Control Port Registers retain settings.

Headphone Amp

Powered Down

20 µs delay (DAC

only)

Stand-By

Transition

1. Pops suppressed.

ERROR: MCLK removed

Analog Output Freeze

1. Aout bias = last audio sample.

2. DAC Modulators stop operation.

3. Audible pops.

Figure 22. Initialization Flowchart

42 DS679F1

4.10 Software Mode

The control port is used to access the registers allowing the CODEC to be configured for the desired operational modes and formats. The operation of the control port may be completely asynchronous with r espect to the audio sample rates. However, to avoid potential interference problems, the control port pins should remain static if no operation is required.

The control port operates in two modes: SPI and I²C, with the CODEC acting as a slave device. Software Mode is selected if there is a high-to-low transition on the AD0/CS high. I²C Mode is selected by connecting the AD0/CS manently selecting the desired AD0 bit address state.

4.10.1 SPI Control

In Software Mode, CS is the CS42L51 ch ip-select sign al, CCLK is the contro l port bit clock (input into the CS42L51 from the microcontroller), CDIN is the input data line from the microcontroller. Data is clocked in on the rising edge of CCLK. The CODEC will only support write operations. Read request will be ignored.

CS42L51

pin after the RESET pin has been brought

pin through a resistor to VL o r DGND, thereby pe r-

Figure 23 shows the operation of the control port in Software Mode. To write to a register, bring CS

The first seven bits on CDIN form the chip address and must be 1001010. The eighth bit is a read/write indicator (R/W which is set to the address of the register that is to be updated. The next eight bits are the data which will be placed into the register designated by the MAP.

There is MAP auto-increment capability, enabled by the INCR bit in the MAP register. If INCR is a zero, the MAP will stay constant for successive read or writes. If INCR is set to a 1, the MAP will auto-increment after each byte is read or written, allowing block reads or writes of successive registers.

0 1 2 3 8 9 12 16 1710 11 13 14 15

CCLK

CDIN

4.10.2 I²C Control

In I²C Mode, SDA is a bidirectional data line. Data is clocked into and out of the part by the clock, SCL. There is no CS through a resistor to VL or DGND as desired. The state of the pin is sensed while the reset.

), which should be low to write. The next eight bits form the Memory Addr ess Pointer (MAP),

4 5 6 7

CHIP ADDRESS (WRITE) MAP BYTE DATA

1 0 0 1 0 1 0 0

Figure 23. Control Port Timing in SPI Mode

INCR 6 5 4 3 2 1 0 7 6 1 0

DATA +n

7 6 1 0

pin. Pin AD0 forms the least significant bit of the chip address and should be connected

CS42L51 is being

low.

The signal timings for a read and write cycle are shown in Figure 24 and Figure 25. A Start condition is defined as a falling transition of SDA while the clock is high. A Stop condition is a rising transition while the clock is high. All other transitions of SDA occur while the clock is low. The first byte sent to the

CS42L51

after a Start condition consists of a 7-bit chip address field and a R/W bit (high for a read, low for a write). The upper 6 bits of the 7-bit address field are fixed at 100101. To communicate with a address field, which is the first byte sent to the the AD0 pin. The eighth bit of the address is the R/W

CS42L51, should match 100101 followed by the setting of

bit. If the operation is a write, the next byte is the

CS42L51, the chip

Memory Address Pointer (MAP) which selects the register to be read or written. If the op eration is a read,

DS679F1 43

CS42L51

the contents of the register pointed to by the MAP will be output. Setting the auto-increment bit in MAP allows successive reads or writes of consecutive registers. Each byte is separated by an acknowledge bit. The ACK bit is output from the the microcontroller after each transmitted byte.

CS42L51 after each input byte is read and is input to the CS42L51 from

SCL

SDA

0 1 2 3 8 9 12 16 17 18 1910 11 13 14 15 27 28

4 5 6 7 24 25

SCL

DATA +n

SDA

CHIP ADDRESS (WRITE) MAP BYTE DATA

1 0 0 1 0 1 AD0 0

START

INCR 6 5 4 3 2 1 0 7 6 1 0 7 6 1 0 7 6 1 0

ACK

DATA +1

Figure 24. Control Port Timing, I²C Write

2 3 10 11 17 18 19 25

CHIP ADDRESS (WRITE)

1 0 0 1 0 1 AD0 0

START

MAP BYTE

INCR 6 5 4 3 2 1 0

ACK

168 9 12 13 14 154 5 6 7 0 1 20 21 22 23 24

STOP

ACK

START

CHIP ADDRESS (READ)

1 0 0 1 0 1 AD0 1

26 27 28

DATA

7 0 7 0 7 0

ACK

DATA +1

ACK

DATA + n

Figure 25. Control Port Timing, I²C Read

Since the read operation cannot set the MAP, an aborted write operation is used as a preamble. As shown in Figure 25, the write operation is aborted after the acknowledge for the MAP byte by sending a stop condition. The following pseudocode illustrates an aborted write operation followed by a read operation.

Send start condition.

ACKACKACK

STOP

ACK

STOP

Send 100101x0 (chip address & write operation). Receive acknowledge bit. Send MAP byte, auto-increment off. Receive acknowledge bit. Send stop condition, aborting write. Send start condition. Send 100101x1 (chip address & read operation). Receive acknowledge bit. Receive byte, contents of selected register. Send acknowledge bit. Send stop condition.

Setting the auto-increment bit in the MAP allows successive reads or writes of consecutive registers. Each byte is separated by an acknowledge bit.

44 DS679F1

4.10.3 Memory Address Pointer (MAP)

The MAP byte comes after the address byte and selects the register to be read or written. Refer to the pseudo code above for implementation details.

4.10.3.1 Map Increment (INCR)

The device has MAP auto-increment capability enabled by the INCR bit (the MSB) of the MAP. If INCR is set to 0, MAP will stay constant for successive I²C writes or reads and SPI writes. If INCR is set to 1, MAP will auto-increment after each byte is read or written, allowing block reads or writes of successive registers.

CS42L51

DS679F1 45

CS42L51

5. REGISTER QUICK REFERENCE

Software mode register defaults are as shown. “Reserved” registers must maintain their default state.

AddrFunction76543210

01h ID Chip_ID4 Chip_ID3 Chip_ID2 Chip_ID1 Chip_ID0 Rev_ID2 Rev_ID1 Rev_ID0

p49

default

02h Power Ctl. 1 Reserved

p49

default

03h Speed Ctl. &

Power Ctl. 2

p50

default

04h Interface Ctl.

p52

default

05h MIC Control

& Misc.

p53

default

06h

ADC Control ADCB_HPFENADCB_HP

p54

default

07h ADC Input

Select , Invert, Mute

p56

default

08h DAC Output

Control

p57

default

09h

DAC Control DATA_SEL1 DATA_SEL0

p58

default

0Ah ALCA SZC &

PGAA Volume

p59

default

0Bh ALCB SZC &

PGAB Volume

p59

default

0Ch ADCA Atten-

uator

p60

default

0Dh ADCB Atten-

uator

11011001

PDN_DACB PDN_DACA dPDN_PGAB PDN_PGAA PDN_ADCB PDN_ADCA

AUTO SPEED1 SPEED0 3-ST_SP

10101110

SDOUT->SDIN

00000000

ADC_SNGVOL ADCB_

00000000

10100000

AINB_MUX1 AINB_MUX0AINA_MUX1 AINA_MUX0 INV_ADCB INV_ADCA ADCB_

00000000

HP_GAIN2 HP_GAIN1 HP_GAIN0

01100000

00000110

ALCA_SR

DIS

00000000

ALCB_SR

DIS

00000000

ADCA_

ATT7

00000000

ADCB_

ATT7

00 0000

PDN_MICB PDN_MICA PDN_

MICBIAS

M/S

DBOOST

FRZ

ALCA_ZC

DIS

ALCB_ZC

DIS

ADCA_

ATT6

ADCB_

ATT6

DAC_DIF2 DAC_DIF1 DAC_DIF0 ADC_I²S/LJ DIGMIX MICMIX

ADCA_

DBOOST

ADCA_HPFENADCA_HP

FREEZE Reserved

Reserved

ADCA_

ATT5

ADCB_

ATT5

MICBIAS_

SEL

FRZ

DAC_SNG

VOL

PGAA

VOL4

PGAB

VOL4

ADCA_

ATT4

ADCB_

ATT4

MICBIAS_

LVL1

SOFTB ZCROSSB SOFTA ZCROSSA

INV_PCMB INV_PCMA

DEEMPH AMUTE DAC_SZC1 DAC_SZC0

PGAA

VOL3

PGAB

VOL3

ADCA_

ATT3

ADCB_

ATT3

MICBIAS_

LVL0

PGAA VOL2

PGAB VOL2

ADCA_

ATT2

ADCB_

ATT2

MICB_

BOOST

MUTE

DACB_

MUTE

PGAA

VOL1

PGAB

VOL1

ADCA_

ATT1

ADCB_

ATT1

PDN

MCLKDIV2

MICA_

BOOST

ADCA_

MUTE

DACA_

MUTE

PGAA

VOL0

PGAB

VOL0

ADCA_

ATT0

ADCB_

ATT0

46 DS679F1

CS42L51

AddrFunction76543210

p60

default

0Eh Vol. Control

ADCMIXA

p61

default

0Fh Vol. Control

ADCMIXB

p61

default

10h Vol. Control

PCMMIXA

p62

default

11h Vol. Control

PCMMIXB

p62

default

12h BEEP Freq. &

OnTime

p62

default

13h BEEP Off

Time & Vol.

p63

default

14h BEEP Con-

trol & Tone Config

p64

default

15h

Tone Control TREB3 TREB2 TREB1 TREB0 BASS3 BASS2 BASS1 BASS0

p65

default

16h Vol. Control

AOUTA

p66

default

17h Vol. Control

AOUTB

p66

default

18h PCM & ADC

Channel Mixer

p67

default

19h Limiter

Threshold & SZC Disable

p67

default

00000000

MUTE_ADC

MIXA

10000000

MUTE_ADC

MIXB

10000000

MUTE_PCM

MIXA

10000000

MUTE_PCM

MIXB

10000000

FREQ3 FREQ2 FREQ1 FREQ0 ONTIME3 ONTIME2 ONTIME1 ONTIME0

00000000

OFFTIME2 OFFTIME1 OFFTIME0 BPVOL4 BPVOL3 BPVOL2 BPVOL1 BPVOL0

00000000

REPEAT BEEP

00000000

10001000

AOUTA_

VOL7

00000000

AOUTB_

VOL7

00000000

PCMA1 PCMA0 PCMB1 PCMB0 ADCA1 ADCA0 ADCB1 ADCB0

00000000

MAX2 MAX1 MAX0 CUSH2 CUSH1 CUSH0 LIM_SRDIS LIM_ZCDIS

00000000

ADCMIXA

VOL6

ADCMIXB

VOL6

PCMMIXA

VOL6

PCMMIXB

VOL6

AOUTA_

VOL6

AOUTB_

VOL6

ADCMIXA

VOL5

ADCMIXB

VOL5

PCMMIXA

VOL5

PCMMIXB

VOL5

Reserved

AOUTA_

VOL5

AOUTB_

VOL5

ADCMIXA

VOL4

ADCMIXB

VOL4

PCMMIXA

VOL4

PCMMIXB

VOL4

TREB_CF1 TREB_CF0 BASS_CF1 BASS_CF0 TC_EN

AOUTA_

VOL4

AOUTB_

VOL4

ADCMIXA

VOL3

ADCMIXB

VOL3

PCMMIXA

VOL3

PCMMIXB

VOL3

AOUTA_

VOL3

AOUTB_

VOL3

ADCMIXA

VOL2

ADCMIXB

VOL2

PCMMIXA

VOL2

PCMMIXB

VOL2

AOUTA_

VOL2

AOUTB_

VOL2

ADCMIXA

VOL1

ADCMIXB

VOL1

PCMMIXA

VOL1

PCMMIXB

VOL1

AOUTA_

VOL1

AOUTB_

VOL1

ADCMIXA

VOL0

ADCMIXB

VOL0

PCMMIXA

VOL0

PCMMIXB

VOL0

AOUTA_

VOL0

AOUTB_

VOL0

DS679F1 47

CS42L51

AddrFunction76543210

1Ah Limiter Con-

fig & Release Rate

p69

default

1Bh Limiter Attack

Rate

p70

default

1Ch ALC Enable

& Attack Rate

p70

default

1Dh ALC Release

Rate

p71

default

1Eh ALC Thresh-

old

p71

default

1Fh Noise Gate

Config

p72

default

20h Status Reserved SP_CLKERRSPEB_OVFL SPEA_OVFL PCMA_OVFL PCMB_OVFL

LIMIT_EN LIMIT_ALL

01111111

Reserved Reserved

00000000

ALC_ENB ALC_ENA ALC_ARATE5AALC_RATE4ALC_ARATE3ALC_ARATE2ALC_ARATE1ALC_ARATE

00000000

Reserved Reserved

00111111

MAX2 MAX1 MAX0 MIN2 MIN1 MIN0

00000000

NG_ALL NG_EN NG_BOOST THRESH2 THRESH1 THRESH0 NGDELAY1 NGDELAY0

00000000

LIM_RRATE5LIM_RRATE4LIM_RRATE3LIM_RRATE2LIM_RRATE1LIM_RRATE

LIM_ARATE5 LIM_ARATE4 LIM_ARATE3 LIM_ARATE2 LIM_ARATE1 LIM_ARATE0

ALC_RRATE5ALC_RRATE4ALC_RRATE3ALC_RRATE2ALC_RRATE1ALC_RRATE

Reserved Reserved

ADCA_OVFL ADCB_OVFL

p73

default

21h Charge Pump

Frequency

p74

default

00000000

CHRG_ FREQ3

01010000

CHRG_

FREQ2

CHRG_ FREQ1

CHRG_ FREQ0

Reserved Reserved Reserved Reserved

48 DS679F1

CS42L51

6. REGISTER DESCRIPTION

All registers are read/write except for the ch ip I.D. and Revision Register and In terrupt Status Register which are read only. See the following bit definition tables for bit assignment information. The default state of each bit after a power-up sequence or reset is listed in each bit description. All “Reserved” registers must maintain their default state.

Note: Certain functions are only available when the “Signal Processing Engine to DAC” option is selected using

the DATA_SEL[1:0] bits, as described in section “DAC Data Selection (DATA_SEL[1:0])” on page 58.

6.1 Chip I.D. and Revision Register (Address 01h) (Read Only)

76543210

Chip_ID4 Chip_ID3 Chip_ID2 Chip_ID1 Chip_ID0 Rev_ID2 Rev_ID1 Rev_ID0

Chip I.D. (Chip_ID[4:0])

Default: 11011 Function: I.D. code for the CS42L51. Permanently set to 11011.

Chip Revision (Rev_ID[2:0])

Default: 001 Function: CS42L51 revision level. Revision B is coded as 001. Revision A is coded as 000.

6.2 Power Control 1 (Address 02h)

76543210

Reserved PDN_DACB PDN_DACA PDN_PGAB PDN_PGAA PDN_ADCB PDN_ADCA PDN

Notes:

1. To activate the power-down sequence fo r individual channels (A or B,) both channels must first be po wered down either by enabling the PDN bit or by enabling the power-down bits for both channels. Enabling the power-down bit on an individual channel basis after the CODEC has fully powered up will mute the selected channel without achieving any po we r sav ing s.

Recommended channel power-down sequence: 1.) Ena ble the PDN bit, 2.) enable power-do wn for the se- lect channels, 3.) disable the PDN bit.

Power Down DAC X (PDN_DACX)

Default: 0 0 - Disable

1 - Enable Function: DAC channel x will either enter a power-down or muted state when this bit is enabled. See Note 1 above.

DS679F1 49

CS42L51

Power Down PGA X (PDN_PGAX)

Default: 0 0 - Disable

1 - Enable Function: PGA channel x will either enter a power-down or muted state when this bit is enabled. See Power Control

1 (Address 02h) on page 49 above.

This bit is used in conjunction with AINx_MUX bits to determine the analog input path to the ADC. Refer to

“ADCX Input Select Bits (AINX_MUX[1:0])” on page 56 for the required settings.

Power Down ADC X (PDN_ADCX)

Default: 0 0 - Disable

1 - Enable Function: ADC channel x will either enter a power-down or muted state when this bit is enabled. See Note 1 on page

49.

Power Down (PDN)

Default: 0 0 - Disable

1 - Enable Function: The entire CODEC will enter a low-power state when this function is enabled. The contents of the control

port registers are retained in this mode.

6.3 MIC Power Control & Speed Control (Address 03h)

76543210

AUTO SPEED1 SPEED0 3-ST_SP PDN_MICB PDN_MICA PDN_MICBIAS MCLKDIV2

Auto-Detect Speed Mode (AUTO)

Default: 1 0 - Disable

1 - Enable Function: Enables the auto-detect circuitry for detecting the speed mode of the CODEC when o perating a s a slave.

When AUTO is enabled, the MCLK/LRCK ratio must be implemented according to Table 3 on page 39. The SPEED[1:0] bits are ignored when this bit is enabled. Speed is determined by the MCLK/LRCK ratio.

50 DS679F1

CS42L51

Speed Mode (SPEED[1:0])

Default: 01 11 - Quarter-Speed Mode (QSM) - 4 to 12.5 kHz sample rates

10 - Half-Speed Mode (HSM) - 12.5 to 25 kHz sample rates 01 - Single-Speed Mode (SSM) - 4 to 50 kHz sample rates 00 - Double-Speed Mode (DSM) - 50 to 100 kHz sample rates

Function: Sets the appropriate speed mode for the CODEC in Master or Slave Mode. QSM is optimized for 8 kHz sam-

ple rate and HSM is optimized for 16 kHz sample rate . These bits are ignored when the AUTO bit is enabled (see Auto-Detect Speed Mode (AUTO) above).

Tri-State Serial Port Interface (3ST_SP)

Default: 0 0 - Disable

1 - Enable Function: When enabled and the device is configured as a master, all serial port outputs are place in a high impedan ce

state. If the serial port is configured as a slave, only the SDOUT pin will be placed in a high-impedance state. The other signals will remain as inputs.

Power Down MIC X (PDN_MICX)

Default: 1 0 - Disable

1 - Enable Function: When enabled, the microphone pre-amplifier for channel x will be in a power-down state.

Power Down MIC BIAS (PDN_MICBIAS)

Default: 1 0 - Disable

1 - Enable Function: When enabled, the microphone bias circuit will be in a power-down state.

MCLK Divide By 2 (MCLKDIV2)

Default: 0 0 - Disabled

1 - Divide by 2 Function: Divides the input MCLK by 2 prior to all internal circuitry. This bit is ignored when the AUTO bit is disabled

in Slave Mode.

DS679F1 51

CS42L51

6.4 Interface Control (Address 04h)

76543210

SDOUT->SDIN M/S

SDOUT to SDIN Loopback (SDOUT->SDIN)

Default: 0 0 - Disabled; SDOUT internally disconnected from SDIN

1 - Enabled; SDOUT internally connected to SDIN Function: Internally loops the signal on the SDOUT pin to SDIN.

Master/Slave Mode (M/S)

Default: 0 0 - Slave

1 - Master Function: Selects either master or slave operation for the serial port.

DAC Digital Interface Format (DAC_DIF[2:0])

DAC_DIF2 DAC_DIF1 DAC_DIF0 ADC_I²S/LJ DIGMIX MICMIX

Default = 000

DAC_DIF[2:0] Description Figure

000 Left-Justified, up to 24-bit data 20 on page 41 001 I²S, up to 24-bit data 19 on page 40 010 Right-Justified, 24-bit data 21 on page 41

011 Right-Justified, 20-bit data 21 on page 41 100 Right-Justified, 18-bit data 21 on page 41 101 Right-Justified, 16-bit data 21 on page 41

110 Reserved 100 Reserved -

Function: Selects the digital interface format used for the data in on SDIN. The required relationship between the

Left/Right clock, serial clock and serial data is defined by the Digital Interface Format and the options are detailed in the section “Digital Interface Formats” on page 40.

52 DS679F1

CS42L51

ADC I²S or Left-Justified (ADC_I²S/LJ)

Default: 0 0 - Left-Justified

1 - I²S Function: Selects either the I²S or Left-Justified digital interface format for the data on SDOUT. The required relation-

ship between the Left/Right clock, serial clock and serial data is defined by the Digital Interface Format and the options are detailed in this section .

Digital Mix (DIGMIX)

Default: 0

DIGMIX DATA_SEL[1:0] Mix Selected

0 xx No Mix: ADC to ADC serial port, SDOUT data.

00 No Mix: SDIN data to ADC serial port, SDOUT data.

Function:

01 Mix: ADC + SDIN data to ADC serial port, SDOUT data. 10 No Mix: ADC to ADC serial port, SDOUT data.

11 Reserved

Selects between the ADC or a di gital mix of the ADC and DAC into th e seria l port to t he SDOUT pin. Th is mix function is affected by the data select bits DATA_SEL[1:0].

Microphone Mix (MICMIX)

Default: 0 0 - Disabled; No Mix: Left/Right Channel to ADC serial port, SDOUT.

1 - Enabled; Mix: Differential mix ((A-B)/2)to ADC serial port, SDOUT. Function: Selects between the ADC stereo mix or a differential mix of analog inputs A and B.

6.5 MIC Control (Address 05h)

76543210

ADC_SNGVOL ADCB_DBOOST ADCA_DBOOST MICBIAS_SEL MICBIAS_LVL1 MICBIAS_LVL0 MICB_BOOST MICA_BOOST

ADC Single Volume Control (ADC_SNGVOL)

Default: 0 0 - Disabled

1 - Enabled Function: The individual PGA Volume (PGAx_VOLx) and ADC channel attenuation (ADCx_ATTx) levels as well as

the ALC A and B enable (ALC_ENx) are independ ently controlled by their respecti ve control registers when this function is disabled. When enabled, the volume on both channels is determined by the ADCA Attenuator Control register, or the PGAA Control register, and the ADCB Attenuator and PGAB Control registers are ignored. The ALC enable control for channel B is controlled by the ALC A enable whe n the ADC_SNGVOL bit is enabled and the ALC_ENB control register is ignored.

DS679F1 53

CS42L51

ADCx 20 dB Digital Boost (ADCx_DBOOST)

Default: 0 0 - Disabled

1 - Enabled Function:

Applies a 20 dB digital gain to the input signal on ADC channel x, regardless of the input path.

MIC Bias Select (MICBIAS_SEL)

Default: 0 0 - MICBIAS on AIN3B/MICIN2 pin

1 - MICBIAS on AIN2B pin Function:

Determines the output pin for the internally generated MICBIAS signal. If set to ‘0’b, the MICBIAS is output on the AIN3B/MICIN2 pin. If set to ‘1’b, the MICBIAS is output on the AIN2B pin.

MIC Bias Level (MICBIAS_LVL[1:0])

Default: 00 00 - 0.8 x VA

01 - 0.7 x VA 10 - 0.6 x VA 11 - 0.5 x VA

Function: Determines the output voltage level of the MICBIAS output.

MIC X Preamplifier Boost (MICX_BOOST)

Default: 0 0 - +16 d B Gain

1 - +32 d B Gain Function:

Determines the amount of gain applied to the microphone preamplifier for channel x.

6.6 ADC Control (Address 06h)

76543210

ADCB_HPFEN ADCB_HPFRZ ADCA_HPFEN ADCA_HPFRZ SOFTB ZCROSSB SOFTA ZCROSSA

ADCX High-Pass Filter Enable (ADCX_HPFEN)

Default: 1 0 - High-pass filter is disabled

1 - High-pass filter is enabled Function:

When this bit is set, the internal high-pass filter will be enabled for ADCx. When set to ‘0’, the high-pass filter will be disabled. For DC measurements, this bit must be cleared to ‘0’. See “ADC Digital Filter Characteris-

tics” on page 15.

54 DS679F1

CS42L51

ADCX High-Pass Filter Freeze (ADCX_HPFRZ)

Default: 0 0 - Continuous DC Subtraction

1 - Frozen DC Subtraction Function: The high-pass filter works by continuously subtracting a measure of the DC offset from the output of the

decimation filter. If the ADCx_HPFRZ bit is taken high during normal operation, the current value of the DC offset is frozen, and this DC offset will continue to be subtracted from the conversion result. For DC measurements, this bit must be set to ‘1’. See “ADC Digital Filter Characteristics” on page 15.

Soft Ramp CHX Control (SOFTX)

Default: 0 0 - Disabled

1 - Enabled Function: Soft Ramp allows level changes to be implemented via an incremental ramp. ADCx_ATT[7:0] digital atten-

uation changes are ramped from the current level to the new level at a rate of 0.125 dB per LRCK period. PGAx_VOL[4:0] gain changes are ramped in 0.5 dB steps every 16 LRCK periods.

Soft Ramp & Zero Cross Enabled When used in conjunction with the ZCROSSx bit, the PGAx_VOL[4:0] gain changes will occur in 0.5 dB steps and be implemented on a signal zero crossing.

Zero Cross CHX Control (ZCROSSX)

Default: 0 0 - Disabled

1 - Enabled Function: Zero Cross Enable dictates that signal level changes will occur on a signal zero crossing to minimize audible

artifacts. The requested level change will occur after a timeout period of 1024 sample periods (approximately 10.7 ms at 48 kHz sample rate) if the signal does not encounter a zero crossing. The zero cross function is independently monitored and implemented for each channel.

Soft Ramp & Zero Cross Enabled When used in conjunction with the SOFTx bit, the PGAx_VOL[4:0] gain changes will occur in 0.5 dB steps and be implemented on a signal zero crossing.

The ADC Attenuator ADCx_ATT[7:0] is not affected by the ZCROSSx bit.

SOFTx ZCROSSx Analog PGA Volume

Digital Attenuator (ADCx_ATT[7:0])

(PGAx_VOL[4:0])

00 01 10

Volume changes immediately. Volume changes immediately. Volume changes at next zero cross time. Volume changes immediately. Volume changes in 0.5 dB steps. Change volume in 0.125 dB steps. Volume changes in 0.5 dB steps at every

signal zero-cross.

Change volume in 0.125 dB steps.

DS679F1 55

CS42L51

6.7 ADCx Input Select, Invert & Mute (Address 07h)

76543210

AINB_MUX1 AINB_MUX0 AINA_MUX1 AINA_MUX0 INV_ADCB INV_ADCA ADCB_MUTE ADCA_MUTE

ADCX Input Select Bits (AINX_MUX[1:0])

Default: 00

PDN_PGAx AINx_MUX[1:0] Selected Path to ADC

0 00 AIN1x-->PGAx 0 01 AIN2x-->PGAx 0 10 AIN3x/MICINx-->PGAx 0 11 AIN3x/MICINx-->Pre-Amp 100AIN1x 101AIN2x 1 10 AIN3x/MICINx 1 11 Reserved

Function: Selects the specified analog input signal into ADCx. The microphone pre-amplifier is only available when

PDN_PGAx is disabled. See Figure 26.

(+16/+32 dB Gain)-->PGAx

AIN1x

AIN2x AIN1x AIN2x

AIN3x / MICINx

+16/

32 dB

MUX

AIN3x

PGA

Decoder

AINx_MUX[1:0]

PDN_PGAx

Figure 26. AIN & PGA Selection

ADCX Invert Signal Polarity (INV_ADCX)

Default: 0 0 - Disabled

1 - Enabled Function:

When enabled, this bit will invert the signal polarity of the ADC x channel.

ADCX Channel Mute (ADCX_MUTE)

Default: 0

MUX

ADC

0 - Disabled 1 - Enabled

Function: The output of channel x ADC will mute when enabled. The muting function is affected by the ADCx Soft bit

(SOFT).

56 DS679F1

CS42L51

6.8 DAC Output Control (Address 08h)

76543210

HP_GAIN2 HP_GAIN1 HP_GAIN0

Headphone Analog Gain (HP_GAIN[2:0])

Default: 011

HP_GAIN[2:0] Gain Setting

000 0.3959 001 0.4571 010 0.51 11 011 0.6047 100 0.7099 101 0.8399 110 1.0000 1 11 1.1430

Function: These bits select the gain multiplier for the headphone/line outputs. See “Line Output Voltage Characteri s-

tics” on page 18 and “Headphone Output Power Characteristics” on page 19.

DAC_

SNGVOL

INV_PCMB INV_PCMA DACB_MUTE DACA_MUTE

DAC Single Volume Control (DAC_SNGVOL)

Default: 0 Function: The individual channel volume levels are independently controlled by their respective Volume Control reg-

isters when this function is disabled. When enabled, the volume on all channels is determined by the AOUTA Volume Control register and the AOUTB Volume Control register is ignored.

PCMX Invert Signal Polarity (INV_PCMX)

Default: 0 0 - Disabled

1 - Enabled Function: When enabled, this bit will invert the signal polarity of the PCM x channel.

DACX Channel Mute (DACX_MUTE)

Default: 0 0 - Disabled

1 - Enabled Function: The output of channel x DAC will mute when enabled. The muting function is affected by the DACx Soft and

Zero Cross bits (DACx_SZC[1:0]).

DS679F1 57

CS42L51

6.9 DAC Control (Address 09h)

76543210

DATA_SEL1 DATA_SEL0 FREEZE Reserved DEEMPH AMUTE DAC_SZC1 DAC_SZC0

DAC Data Selection (DATA_SEL[1:0])

Default: 00 00 - PCM Serial Port to DAC

01 - Signal Processing Engine to DAC 10 - ADC Serial Port to DAC 11 - Reserved

Function: Selects the digital signal source for the DAC.

Processing Engine to DAC” option is selected using these bits.

Freeze Controls (FREEZE)

Default: 0 Function: This function will freeze the previous settings of, and allow modifications to be made to all control port reg-

isters without the changes taking effect until the FREEZE is disabled. To have multiple chang es in the control port registers take effect simultaneously, enable the FREEZE bit, make all register changes, then disable the FREEZE bit.

DAC De-Emphasis Control (DEEMPH)

Default: 0 0 - No De-Emphasis

1 - De-Emphasis Enabled Function:

Note: The DATA_SEL[1:0] bits in reg09h must be set to ‘01’b to enable function control.

Enables the digital filter to apply the standard 15µs/50µs digital de-emphasis filter response for a sample rate of 44.1 kHz.

Note: Certain functions are only available when the “Signal

Analog Output Auto MUTE (AMUTE)

Default: 0 0 - Auto Mute Disabled

1 - Auto Mute Enabled Function: Enables (or disables) Automatic Mute of the analog outputs after 8192 “0” samples on each digital input

channel.

58 DS679F1

CS42L51

DAC Soft Ramp and Zero Cross Control (DAC_SZC[1:0])

Default = 10 00 - Immediate Change

01 - Zero Cross 10 - Soft Ramp 11 - Soft Ramp on Zero Crossings

Function:

Note: The DATA_SEL[1:0] bits in reg09h must be set to ‘01’b to enable function control

Immediate Change When Immediate Change is selected all volume-level changes will take effect immediately in one step. Zero Cross This setting dictates that signal-level changes, either by gain changes, attenuation changes or muting, will

occur on a signal zero crossing to minimize audible artifacts. The requested level change will occur after a timeout period between 1024 and 2048 sample periods (21.3 ms to 42.7 ms at 48 kHz sample rate) if the signal does not encounter a zero crossing. The zero cross function is independently monitored and implemented for each channel.

Soft Ramp

Note: The LIM_SRDIS bit is ignored.

Soft Ramp allows level changes, either by gain changes, attenuati on changes or muting, to be implemente d by incrementally ramping, in 1/8 dB steps, from the current level to the new level at a rate of 0.5 dB per 4 left/right clock periods.

Soft Ramp on Zero Crossing This setting dictates that signal-level changes, either by gain changes, attenuation changes or muting, will

occur in 1/8 dB steps and be implemented on a signal zero crossing. The 1/8 dB level change will occur after a timeout period between 512 and 1024 sample periods (10.7 ms to 21.3 ms at 48 kHz sample rate) if the signal does not encounter a zero crossing. The zero cross fu nctio n is indepe nde ntly mon ito red an d implemented for each channel.

Note: The LIM_SRDIS bit is ignored.

6.10 ALCX & PGAX Control: ALCA, PGAA (Address 0Ah) & ALCB, PGAB (Address 0Bh)

76543210

ALCX_SRDIS ALCX_ZCDIS Reserved PGAX_VOL4 PGAX_VOL3 PGAX_VOL2 PGAX_VOL1 PGAX_VOL0

ALCX Soft Ramp Disable (ALCX_SRDIS)

Default: 0 0 - Off

1 - On Function:

Overrides the SOFTx bit setting for the ADC. When this bit is set, the ALC attack rate in the PGA will not be dictated by the soft ramp setting. ALC volume-level changes will take effect in one step.

DS679F1 59

CS42L51

ALCX Zero Cross Disable (ALCX_ZCDIS)

Default: 0 0 - Off

1 - On Function:

Overrides the ZCROSSx bit setting for the ADC. When this bit is set, the ALC attack rate in the PGA will not be dictated by the zero cross setting. ALC volume-level changes will take effect immediately in one step.

PGA X Gain Control (PGAX_VOL[4:0])

Default: 00000

Binary Code Volume Setting

11000 +12 dB

··· ···

01010 +5 dB

··· ···

00000 0 dB

11111 -0.5 dB 11110 -1 dB

··· ··· 11001 -3 dB 11010 -3 dB

Function: The PGAx Gain Control register allows independent setting of the sig nal levels in 0.5 dB increments as dic-

tated by the ADCx Soft and Zero Cross bits (SOFTx & ZCROSSx) from +12 dB to -3 dB. Gain settings are decoded as shown in the table above. The gain changes are implemented as dictated by the ALCX Soft & Zero Cross bits (ALCX_SZC). Levels are decoded as described in the table above.

Note: When the ALC is enabled, the PGA is automatic ally controlled and should no t be adjusted manu-

ally.

6.11 ADCx Attenuator: ADCA (Address 0Ch) & ADCB (Address 0Dh)

76543210

ADCx_ATT7 ADCx_ATT6 ADCx_ATT5 ADCx_ATT4 ADCx_ATT3 ADCx_ATT2 ADCx_ATT1 ADCx_ATT0

ADCX Attenuation Control (ADCX_ATT[7:0])

Default: 00h

Binary Code Volume Setting

0111 1111 0 dB

··· ···

0000 0000 0 dB

1111 1111 -1 dB

1111 1110 -2 dB

··· ···

1010 0000 -96 dB

··· ···

1000 0000 -96 dB

60 DS679F1

CS42L51

Function: The level of ADCX can be adjusted in 1.0 dB increments as dictated by the ADCx Soft and Zero Cro ss bits

(SOFTx & ZCROSSx) from 0 to -96 dB. Levels are d ecoded in two’s complement, as shown in the ta ble above.

Note: When the ALC is enabled, the Attenuator and PGA volume is automatically controlled and should

not be adjusted manually.

6.12 ADCx Mixer Volume Control: ADCA (Address 0Eh) & ADCB (Address 0Fh)

76543210

MUTE_ADCMIXx ADCMIXx_VOL6 ADCMIXx_VOL5 ADCMIXx_VOL4 ADCMIXx_VOL3 ADCMIXx_VOL2 ADCMIXx_VOL1 ADCMIXx_VOL0

Note: The DATA_SEL[1:0] bits in reg09h must be set to ‘01’b to enable function control in this register.

ADCX Mixer Channel Mute (MUTE_ADCMIXX)

Default: 1 0 - Disabled

1 - Enabled Function: The ADC channel X input to the output mixer will mute when enabled. The muting function is affected by

the DACX Soft and Zero Cross bits (DACX_SZC[1:0]).

ADCX Mixer Volume Control (ADCMIXX_VOL[6:0])

Default = 000 0000

Binary Code Volume Setting

001 1000 +12.0 dB

··· ···

000 0000 0 dB

111 1111 -0.5 dB 111 1110 -1.0 dB

··· ···

001 1001 -51.5 dB

Function: The level of the ADCX input to the output mixer can be adjusted in 0.5 dB increments as dictated by the

DACX Soft and Zero Cross bits (DACX_SZC[1:0]) from +12 to -51.5 dB. Levels are decoded as shown in the table above.

DS679F1 61

6.13 PCMX Mixer Volume Control: PCMA (Address 10h) & PCMB (Address 11h)

76543210

MUTE_

PCMMIXx

Note: The DATA_SEL[1:0] bits in reg09h must be set to ‘01’b to enable function control in this register.

PCMX Mixer Channel Mute (MUTE_PCMMIXX)

Default = 1 0 - Disabled

1 - Enabled Function: The PCM channel X input to the output mixer will mute when enabled. The muting function is affected by

the DACX Soft and Zero Cross bits (DACX_SZC[1:0]).

PCMX Mixer Volume Control (PCMMIXX_VOL[6:0])

Default: 000 0000

PCMMIXx_

VOL6

PCMMIXx_

VOL5

PCMMIXx_

VOL4

Binary Code Volume Setting

001 1000 +12.0 dB

··· ···

000 0000 0 dB

111 1111 -0.5 dB 111 1110 -1.0 dB

··· ···

001 1001 -51.5 dB

PCMMIXx_

VOL3

PCMMIXx_

VOL2

PCMMIXx_

VOL1

CS42L51

PCMMIXx_

VOL0

Function: The level of the PCMX input to the output mixer can be ad justed in 0.5 dB increments as dictated by the

DACX Soft and Zero Cross bits (DACX_SZC[1:0]) from +12 to -51.5 dB. Levels are decoded as described in the table above.

6.14 Beep Frequency & Timing Configuration (Address 12h)

76543210

FREQ3 FREQ2 FREQ1 FREQ0 ONTIME3 ONTIME2 ONTIME1 ONTIME0

Note: The DATA_SEL[1:0] bits in reg09h must be set to ‘01’b to enable function control in this register.

Beep Frequency (FREQ[3:0])

Default: 0000

FREQ[3:0] Frequency

Fs = 12, 24, 48 or 96

kHz

0000 260.87 Hz C4 0001 521.74 Hz C5 0010 585.37 Hz D5 0011 666.67 Hz E5 0100 705.88 Hz F5

Pitch

62 DS679F1

CS42L51

FREQ[3:0] Frequency

Pitch

Fs = 12, 24, 48 or 96

kHz

0101 774.19 Hz G5 0110 888.89 Hz A5

0111 1000.00 Hz B5 1000 1043.4 8 Hz C6 1001 1200.0 0 Hz D6 1010 1333.3 3 Hz E6 1011 1411.76 Hz F6 1100 1600.00 Hz G6 1101 1714.29 Hz A6

1110 2000.00 Hz B6

1111 2181.82 Hz C7

Function: The frequency of the beep signal can be adjusted from 260.87 Hz to 2181.82 Hz. Beep frequency will scale

directly with sample rate, Fs, but is fixed at the nominal Fs within each speed mode. Refer to Figure 15 on

page 36 for single, multiple and continuous beep configurations using the REPEAT and BEEP bits.

Beep On Time Duration (ONTIME[3:0])

Default: 0000

TIME[3:0]

0000 86 ms

··· ···

1111 5.2 s

Fs = 12, 24, 48 or 96 kHz

On Time

Function: The on-duration of the beep signal can be adjusted from approximately 86 ms to 5.2 s. The on-duration will

scale inversely with sample rate, Fs, but is fixed at the nominal Fs within each speed mode. Refer to Figure

15 on page 36 for single-, multiple- and continuous-beep configurations using the REPEAT and BEEP bits.

6.15 Beep Off Time & Volume (Address 13h)

76543210

OFFTIME2 OFFTIME1 OFFTIME0 BPVOL4 BPVOL3 BPVOL2 BPVOL1 BPVOL0

Note: The DATA_SEL[1:0] bits in reg09h must be set to ‘01’b to enable function control in this register.

Beep Off Time (OFFTIME[2:0])

Default: 000

OFFTIME[2:0] Off Time

Fs = 12, 24, 48 or

96 kHz

000 1.23 s 001 2.58 s 010 3.90 s

011 5.20 s 100 6.60 s 101 8.05 s

DS679F1 63

CS42L51

OFFTIME[2:0] Off Time

Fs = 12, 24, 48 or

96 kHz

110 9.35 s

111 10.80 s

Function: The off-duration of the beep signal can be adjusted from approximately 75 ms to 680 ms. The off-duration

will scale inversely with sample rate, Fs, but is fixed at the nominal Fs within each speed mode. Refer to

Figure 15 on page 36 for single-, multiple- and continuous-beep configurations using the REPEAT and

BEEP bits.

Beep Volume (BPVOL[4:0])

Default: 00000

Binary Code Volume Setting

00110 +12.0 dB

··· ···

00000 0 dB

11111 -2 dB 11110 -4 dB

··· ···

00111 -50 dB

Function: The level of the beep into the output mixer can be adjusted in 2.0 dB increments from +12 dB to -50 dB.

Refer to Figure 15 on page 36 for single-, multiple- and continu ous-beep co nfigurations using the REPEAT and BEEP bits. Levels are decoded as described in the table above.

6.16 Beep Configuration & Tone Configuration (Address 14h)

76543210

REPEAT BEEP Reserved TREB_CF1 TREB_CF0 BASS_CF1 BASS_CF0 TC_EN

Note: The DATA_SEL[1:0] bits in reg09h must be set to ‘01’b to enable function control in this register.

Repeat Beep (REPEAT)

Default: 0 0 - Disabled

1 - Enabled Function: This bit is used in conjunction with the BEEP bit to mix a continuous or periodic beep with the analog output.

Refer to Figure 15 on page 36 for a description of each configuration option.

Beep (BEEP)

Default: 0 0 - Disabled

1 - Enabled Function:

64 DS679F1

CS42L51

This bit is used in conjunction with the REPEAT bit to mix a continuous or periodic beep with the analog output. remain ON for the maximum ONTIME duration. Refer to Figu re 15 on page 36 for a d escription of each configuration option.

Treble Corner Frequency (TREB_CF[1:0])

Default: 00 00 - 5 kHz

01 - 7 kHz 10 - 10 kHz 11 - 15 kHz

Function: The treble corner frequency is user selectable as shown above.

Bass Corner Frequency (BASS_CF[1:0])

Default: 00 00 - 50 Hz 01 - 100 Hz 10 - 200 Hz 11 - 250 Hz

Note: Re-engaging the beep before it has completed its initial cycle will cause the beep signal to

Function: The bass corner frequency is user-selectable as shown above.

Tone Control Enable (TC_EN)

Default = 0 0 - Disabled

1 - Enabled Function: The Bass and Treble tone control features are active when this bit is enabled.

6.17 Tone Control (Address 15h)

76543210

TREB3 TREB2 TREB1 TREB0 BASS3 BASS2 BASS1 BASS0

Note: The DATA_SEL[1:0] bits in reg09h must be set to ‘01’b to enable function control in this register.

Treble Gain Level (TREB[3:0])

Default: 1000 dB (No Treble Gain)

Binary Code Gain Setting

0000 +12.0 dB

··· ···

01 11 +1.5 dB 1000 0 dB 1001 -1.5 dB

··· ···

1111 -10.5 dB

DS679F1 65

CS42L51

Function: The level of the shelving treble gain filter is se t by Treble Gain Level. The level can be adjusted in 1.5 dB

increments from +12.0 to -10.5 dB.

Bass Gain Level (BASS[3:0])

Default: 1000 dB (No Bass Gain)

Binary Code Gain Setting

0000 +12.0 dB

··· ···

0111 +1.5 dB 1000 0 dB 1001 -1.5 dB

··· ···

1111 -10.5 dB

Function: The level of the shelving bass gain filter is set by Bass Gain Level. The level can be adjusted in 1.5 dB in-

crements from +10.5 to -10.5 dB.

6.18 AOUTx Volume Control: AOUTA (Address 16h) & AOUTB (Address 17h)

76543210

AOUTx_VOL7 AOUTx_VOL6 AOUTx_VOL5 AOUTx_VOL4 AOUTx_VOL3 AOUTx_VOL2 AOUTx_VOL1 AOUTx_VOL0

Note: The DATA_SEL[1:0] bits in reg09h must be set to ‘01’b to enable function control in this register.

AOUTX Volume Control (AOUTX_VOL[7:0])

Default = 00h

Binary Code Volume Setting

0001 1000 +12.0 dB

··· ···

0000 0000 0 dB

1111 1111 -0.5 dB

1111 1110 -1.0 dB

··· ···

0011 0100 -102 dB

··· ···

0001 1001 -102 dB

Function: The analog output levels can be adjusted in 0.5 dB increments from +12 to - 102 dB as dictated by the DAC

Soft and Zero Cross bits (DACX_SZC[1:0]). Levels are decoded in unsigned binary as described in the table above.

Note: When the limiter is enabled, the AOUT Volume is automatically controlled and should not be ad-

justed manually. Alternative volume control may be achieved using the PCMMIXx_VOL[6:0] bits.

66 DS679F1

CS42L51

6.19 PCM Channel Mixer (Address 18h)

76543210

PCMA1 PCMA0 PCMB1 PCMB0 ADCA1 ADCA0 ADCB1 ADCB0

Note: The DATA_SEL[1:0] bits in reg09h must be set to ‘01’b to enable function control in this register.

Channel Mixer (PCMx[1:0] & ADCx[1:0])

Default: 00

PCMA[1:0]

and/or

AOUTA PCMB[1:0]

ADCB[1:0]

and/or

AOUTB

ADCA[1:0]

00 L 00 R 01 01 10 10

11 R 11 L

LR+

------------

LR+

------------

Function: Implements mono mixes of the left and right channels as well as a left/right channel swap.

6.20 Limiter Threshold SZC Disable (Address 19h)

76543210

MAX2 MAX1 MAX0 CUSH2 CUSH1 CUSH0 LIM_SRDIS LIM_ZCDIS

Note: The DATA_SEL[1:0] bits in reg09h must be set to ‘01’b to enable function control in this register.

Maximum Threshold (MAX[2:0])

Default: 000

MAX[2:0] Threshold

Setting

(dB)

000 0 001 -3 010 -6 011 -9 101 -12 101 -18 110 -24

111 -30

Function: Sets the maximum level, below full scale, at which to limit and attenuate the output signal at the attack rate.

Bass, Treble and digital gain settings that boost the signal beyond the maximum threshold may trigger an attack.

DS679F1 67

CS42L51

Cushion Threshold (CUSH[2:0])

Default: 000

CUSH[2:0] Threshold

Setting

(dB)

000 0 001 -3 010 -6

011 -9 101 -12 101 -18

110 -24

111 -30

Function: Sets a cushion level below full scale. This setting is usually set slightly below the maximum (MAX[2:0])

threshold. The Limiter uses this cushion as a hysteresis point for the input signal as it maintains the signal below the maximum as well as below the cushion setting. This provides a more natural sound as the limiter attacks and releases.

Limiter Soft Ramp Disable (LIM_SRDIS)

Default: 0 0 - Off

1 - On Function: Overrides the DAC_SZC setting. When this bit is set, the Limiter attack and release rate will not be dictated

by the soft ramp setting.

Note: This bit is ignored when the zero-cross function is enabled (i.e. when

DAC_SZC[1:0] = ‘01’b or ‘11’b.)

Limiter Zero Cross Disable (LIM_ZCDIS)

Default: 0 0 - Off

1 - On Function: Overrides the DAC_SZC setting. When this bit is set, the Limiter attack and release rate will not be dictated

by the zero-cross setting.

68 DS679F1

CS42L51

6.21 Limiter Release Rate Register (Address 1Ah)

76543210

LIMIT_EN LIMIT_ALL RRATE5 RRATE4 RRATE3 RRATE2 RRATE1 RRATE0

Note: The DATA_SEL[1:0] bits in reg09h must be set to ‘01’b to enable function control in this register.

Peak Detect and Limiter Enable (LIMIT_EN)

Default: 0 0 - Disabled

1 - Enabled Function: Limits the maximum signal amplitude to prevent clipping when this function is enabled. Peak Signal Limiting

is performed by digital attenu ation. controlled and should not be adjusted manually. Alternative volume control may be realized using the PCMMIXx_VOL[6:0] bits.

Peak Signal Limit All Channels (LIMIT_ALL)

Default: 1 0 - Individual Channel

1 - Both channel A & B

Note: When the limiter is enabled, the AOUT Volume is automatically

Function: When set to 0, the peak signal limiter will limit the maximum signal amplitude to prevent clipping on the spe-

cific channel indicating clipping. The other channels will not be affected. When set to 1, the peak signal limiter will limit the maximum signal amplitude to prevent clipping on both

channels in response to any single channel indicating clipping.

Limiter RELEASE Rate (RRATE[5:0])

Default: 111111

Binary Code Release Time

000000 Fastest Release

··· ···

111111 Slowest Release

Function: Sets the rate at which the limiter releases the digital attenuation from levels below the minimum setting in

the limiter threshold register, and returns the analog output level to the AOUTx_VOL[7:0] setting. The limiter release rate is user selectable but is also a function of the sampling frequency, Fs, and the

DAC_SZC setting unless the disable bit is enabled.

DS679F1 69

CS42L51

6.22 Limiter Attack Rate Register (Address 1Bh)

76543210

Reserved Reserved ARATE5 ARATE4 ARATE3 ARATE2 ARATE1 ARATE0

Note: The DATA_SEL[1:0] bits in reg09h must be set to ‘01’b to enable function control in this register.

Limiter Attack Rate (ARATE[5:0])

Default: 000000

Binary Code Attack Time

000000 Fastest Attack

··· ···

111111 Slowest Attack

Function: Sets the rate at which the limiter attenuates the analog output from levels above the maximum setting in the

limiter threshold register. The limiter attack rate is user-selectable but is also a function of the sampling frequency, Fs, and the

DAC_SZC setting unless the disable bit is enabled.

6.23 ALC Enable & Attack Rate (Address 1Ch)

76543210

ALC_ENB ALC_ENA ALC_ARATE5 ALC_ARATE4 ALC_ARATE3 ALC_ARATE2 ALC_ARATE1 ALC_ARATE0

ALC Enable (ALC_ENX)

Default: 0 0 - Disabled

1 - Enabled Function: Enables automatic level control for ADC channel x.

Note: When the ALC is enabled, the Attenuator and PGA volume is automatically controlled and should

not be adjusted manually.

ALC Attack Rate (ARATE[5:0])

Default: 000000

Binary Code Attack Time

000000 Fastest Attack

··· ···

111111 Slowest Attack

Function: Sets the rate at which the ALC attenuates the analog input from levels above the maximum setting in the

ALC threshold register. The limiter attack rate is user-selectable but is also a function of the sampling fr equency, Fs, and the SOFTx

& ZCROSSx bit settings unless the disable bit for each function is enabled.

70 DS679F1

CS42L51

6.24 ALC Release Rate (Address 1Dh)

76543210

Reserved Reserved ALC_RRATE5 ALC_RRATE4 ALC_RRATE3 ALC_RRATE2 ALC_RRATE1 ALC_RRATE0

ALC Release Rate (RRATE[5:0])

Default: 111111

Binary Code Release Time

000000 Fastest Release

··· ···

111111 Slowest Release

Function: Sets the rate at which the ALC releases the PGA & digital attenuation from levels below the minimum setting

in the ALC threshold register, and returns the input level to the PGA_VOL[4:0] & ADCx_ATT[7:0] setting. The ALC release rate is user selectable, but is also a function of th e sampling frequency, Fs, and the SOFTx & ZCROSS bit settings unless the disable bit for each function is enabled.

6.25 ALC Threshold (Address 1Eh)

76543210

MAX2 MAX1 MAX0 MIN2 MIN1 MIN0 Reserved Reserved

Maximum Threshold (MAX[2:0])

Default: 000

MAX[2:0] Threshold

Setting

(dB)

000 0 001 -3 010 -6

011 -9 100 -12 101 -18

110 -24

111 -30

Function: Sets the maximum level, relative to full scale, at which to limit and attenuate the input signal at the attack

rate.

Minimum Threshold (MIN[2:0])

Default: 000

Threshold

MIN[2:0]

Setting

(dB)

000 0 001 -3 010 -6

DS679F1 71

CS42L51

Threshold

MIN[2:0]

011 -9 100 -12 101 -18

110 -24

111 -30

Function: Sets the minimum level at which to disengage the ALC’s attenuation or amplify the input signal at a rate se t

in the release rate register until levels again reach this minimum threshold. The ALC uses this minimum as a hysteresis point for the input signal a s it maintains the signal below the maximum as well as below the minimum setting. This provides a more natural sound as the ALC attacks and releases.

6.26 Noise Gate Configuration & Misc. (Address 1Fh)

76543210

NG_ALL NG_EN NG_BOOST THRESH2 THRESH1 THRESH0 NGDELAY1 NGDELAY0

Noise Gate Channel Gang (NG_ALL)

Setting

(dB)

Default: 0 0 - Disabled

1 - Enabled Function: Gangs the noise gate function for channel A and B. When enable d, both channels must fall below the thresh-

old setting for the noise gate attenuation to take effect.

Noise Gate Enable (NG_EN)

Default: 0 0 - Disabled

1 - Enabled Function: Enables the noise gate. Maximum attenuation is relative to all gain settings applied.

Noise Gate Boost (NG_BOOST) and Threshold (THRESH[3:0])

Default: 000

THRESH[2:0]

000 -64 dB -34 dB 001 -67 dB -37 dB 010 -70 dB -40 dB 011 -73 dB -43 dB 100 -76 dB -46 dB 101 -82 dB -52 dB 110 Reserved -58 dB 1 11 Reserved -64 dB

Minimum Setting

(NG_BOOST = ‘0’b)

Minimum Setting

(NG_BOOST = ‘1’b)

72 DS679F1

CS42L51

Function: Sets the threshold level of the noise gate. Input signals below the threshold level will be attenuated to -96 dB. NG_BOOST = ‘1’b adds 30 dB to the threshold settings.

Noise Gate Delay Timing (NGDELAY[1:0])

Default: 00 00 - 50 ms

01 - 100 ms 10 - 150 ms 11 - 200 ms

Function: Sets the delay time before the noise gate attacks. Noise gate attenuation is dictated by the SOFTx &

ZCROSS bit settings unless the disable bit for each function is enabled.

6.27 Status (Address 20h) (Read Only)

76543210

Reserved SP_CLKERR SPEA_OVFL SPEB_OVFL PCMA_OVFL PCMB_OVFL ADCA_OVFL ADCB_OVFL

For all bits in this register, a “1” means the associated error condition has occurred at least once since the register was last read. A ”0” means the associated error condition has NOT occurred since the last reading of the register. Reading the register resets all bits to 0.

Serial Port Clock Error (SP_CLK Error)

Default: 0 Function: Indicates an invalid MCLK to LRCK ratio. See “Serial Port Clocking” on page 38 for valid clock ratios.

Note: On initial power up and application of clocks, this bit will be high as the serial port re-synchronizes. Signal Processing Engine Overflow (SPEX_OVFL)

Default: 0 Function:

Indicates a digital overflow condition within the data path after the signal processing engine.

PCMX Overflow (PCMX_OVFL)

Default: 0 Function: Indicates a digital overflow condition within the data path of the PCM mix.

ADC Overflow (ADCX_OVFL)

Default = 0 Function: Indicates that there is an over-range cond ition anywhere in the CS42L51 ADC signal path of each of the

associated ADC’s.

DS679F1 73

CS42L51

6.28 Charge Pump Frequency (Address 21h)

76543210

CHRG_FREQ3CHRG_FREQ2CHRG_FREQ1CHRG_FREQ

Charge Pump Frequency (CHRG_FREQ[3:0])

Default: 0101

N CHRG_FREQ[3:0] Frequency

0 0000

... ...

15 1111

64xFs

---------------- N2+

Function: Alters the clocking frequency of the charge pump in 1/(N+2) fractions of the DAC oversampling rate, 128Fs,

should the switching frequency interfere with other system frequencies such as those in the AM radio band.

Note: Distortion performance may be affected.

Reserved Reserved Reserved Reserved

74 DS679F1

7. ANALOG PERFORMANCE PLOTS

7.1 Headphone THD+N versus Output Power Plots

Test conditions (unless otherwise spec ified): Input test signal is a 99 7 Hz sine wave; measurement bandwidth is 10 Hz to 20 kHz; Fs = 48 kHz. Plots were taken from the CDB42L51 using an Audio Precision analyzer.

-10

-15

VA_HP = VA = 1.8 V

-20

-25

-30

-35

-40

-45

-50

d B

-55

-60

-65

-70

-75

-80

-85

-90

-95

-100 0 80m10m 20m 30m 40m 50m 60m 70m

Figure 27. THD+N vs. Output Power per Channel at 1.8 V (16 Ω load)

CS42L51

G = 0.6047 G = 0.7099 G = 0.8399 G = 1.0000 G = 1.1430

Legend

NOTE: Graph shows the out-

put power per channel (i.e. Output Power = 23 mW into single 16 Ω and 46 mW into stereo 16 Ω with THD+N = 75 dB).

-10

-15

VA_HP = VA = 2.5 V

-20

-25

-30

-35

-40

-45

-50

d B

-55

-60

-65

-70

-75

-80

-85

-90

-95

-100 0 80m10m 20m 30m 40m 50m 60m 70m

Figure 28. THD+N vs. Output Power per Channel at 2.5 V (16 Ω load)

G = 0.6047 G = 0.7099 G = 0.8399 G = 1.0000 G = 1.1430

Legend

NOTE: Graph shows the out-

put power per channel (i.e. Output Power = 44 mW into single 16 Ω and 88 mW into stereo 16 Ω with THD+N = 75 dB).

DS679F1 75

VA_HP = VA = 1.8

-20

-30

-35

-40

-45

-50

-55 d B

-60

-65

-70

-75

-80

-85

-90

-95

-100 0 60m6m 12m 18m 24m 30m 36m 42m 48m 54m

CS42L51

G = 0.6047 G = 0.7099 G = 0.8399 G = 1.0000 G = 1.1430

Legend

NOTE: Graph shows the out-

put power per channel (i.e. Output Power = 22 mW into single 32 Ω and 44 mW into stereo 32 Ω with THD+N = 75 dB).

Figure 29. THD+N vs. Output Power per Channel at 1.8 V (32 Ω load)

-20

VA_HP = VA = 2.5 V

-25

-30

-35

-40

-45

-50

-55

d B

-60

-65

-70

-75

-80

-85

-90

-95

-100 0 60m5m 10m 15m 20m 25m 30m 35m 40m 45m 50m 55m

Figure 30. THD+N vs. Output Power per Channel at 2.5 V (32 Ω load)

G = 0.6047 G = 0.7099 G = 0.8399 G = 1.0000 G = 1.1430

Legend

NOTE: Graph shows the out-

put power per channel (i.e. Output Power = 42 mW into single 32 Ω and 84 mW into stereo 32 Ω with THD+N = 75 dB).

76 DS679F1

7.2 Headphone Amplifier Efficiency

The architecture of the headphone amplifier is that of typical class AB amplifiers. Test conditions (unless otherwise specified): Input test signal is a 997 Hz sine wave; Power Consumption Mode 6 - Stereo Playback w/16 Ω load. HP_GAIN = 1.1430. Best efficiency is realized when the amplifier outputs maximum power.

VA_HP = VA = 1.8 V

CS42L51

Figure 31. Power Dissipation vs. Output Power into Stereo 16 Ω

VA_HP = VA = 1.8 V

Figure 32. Power Dissipation vs. Output Power into Stereo 16 Ω (Log Detail)

DS679F1 77

7.3 ADC_FILT+ Capacitor Effects on THD+N

The value of the capacitor on the ADC_FILT+ pin, 16, affects the low frequency total harmonic distortion + noise (THD+N) performance of the ADC. Larger capacitor values yield significant improvement in THD+N at low frequencies. Figure 33 shows the THD+N versus frequency for the ADC analog input. Plots were taken from the CDB42L51 using an Audio Precision analyzer.

CS42L51

-64

-68

-72

-76

-80

-84

-88

-92

-96

-100 20 20k50 100 200 500 1k 2k 5k 10k

Figure 33. ADC THD+N vs. Frequency w/Capacitor Effects

1 µF

10 µF

22 µF

Legend – Capacitor Value on ADC_FILT+

78 DS679F1

8. EXAMPLE SYSTEM CLOCK FREQUENCIES

8.1 Auto Detect Enabled

CS42L51

Sample Rate

LRCK (kHz)

8 8.1920 12.2880 16.3840 24.5760

11 .025 11.2896 16.9344 22.5792 33.8688

12 12.2880 18.4320 24.5760 36.8640

1024x 1536x 2048x* 3072x*

Sample Rate

LRCK (kHz)

16 8.1920 12.2880 16.3840 24.5760

22.05 11.2896 16.9344 22.5792 33.8688 24 12.2880 18.4320 24.5760 36.8640

512x 768x 1024x* 1536x*

Sample Rate

LRCK (kHz)

32 8.1920 12.2880 16.3840 24.5760

44.1 11.2896 16.9344 22.5792 33.8688 48 12.2880 18.4320 24.5760 36.8640

256x 384x 512x* 768x*

Sample Rate

LRCK (kHz)

64 8.1920 12.2880 16.3840 24.5760

88.2 11.2896 16.9344 22.5792 33.8688 96 12.2880 18.4320 24.5760 36.8640

128x 192x 256x* 384x*

MCLK (MHz)

*The”MCLKDIV2” pin 4 must be set HI.

DS679F1 79

8.2 Auto Detect Disabled

CS42L51

Sample Rate

LRCK (kHz)

8 - 6.1440 8.1920 12.2880 16.3840 24.5760

11 .025 - 8.4672 11.2896 16.9344 22.5792 33.8688

12 6.1440 9.2160 12.2880 18.4320 24.5760 36.8640

512x 768x 1024x 1536x 2048x 3072x

Sample Rate

LRCK (kHz)

16 - 6.1440 8.1920 12.2880 16.3840 24.5760

22.05 - 8.4672 11.2896 16.9344 22.5792 33.8688 24 6.1440 9.2160 12.2880 18.4320 24.5760 36.8640

256x 384x 512x 768x 1024x 1536x

Sample Rate

LRCK (kHz)

32 8.1920 12.2880 16.3840 24.5760

44.1 11.2896 16.9344 22.5792 33.8688 48 12.2880 18.4320 24.5760 36.8640

256x 384x 512x 768x

Sample Rate

LRCK (kHz)

64 8.1920 12.2880 16.3840 24.5760

88.2 11.2896 16.9344 22.5792 33.8688 96 12.2880 18.4320 24.5760 36.8640

128x 192x 256x 384x

MCLK (MHz)

80 DS679F1

9. PCB LAYOUT CONSIDERATIONS

9.1 Power Supply, Grounding

As with any high-resolution converter, the CS42L51 requires careful attention to power supply and grounding arrangements if its potential performance is to be realized. Figure 1 on page 10 shows the recommended power arrangements, with VA and VA_HP connected to clean supplies. VD, which powers the digital circui try, may be run from the system logic supply. Alternatively, VD may be powered from the analog supply via a ferrite bead. In this case, no additional devices should be powered from VD.

Extensive use of power and ground planes, ground plane fill in unused areas and surface mount decoupling capacitors are recommended. Decoupling capa citors sh ould be as close to the pins of the sible. The low value ceramic capacitor should be closest to the pin and should be mounted on the same side of the board as the kept away from the DAC_FILT+/ADC_FILT+ and VQ pins in order to avoid unwanted coupling into the modulators. The DAC_FILT+/ADC_FILT+ an d VQ de co up lin g capa cit or s, p ar ticul ar ly the 0 .1 µF, must be positioned to minimize the electrical path from DAC_FILT+/ADC_FILT+ and AGND. The CDB42L51 e valuation board demonstrates the optimum layout and power supply arrangements.

9.2 QFN Thermal Pad

The CS42L51 is available in a compact QFN package. The under side o f the QFN packag e reveals a larg e metal pad that serves as a thermal relief to provide for maximum heat dissipation. This pad must mate with an equally dimensioned copper pad on the PCB and must be electrically connected to ground. A series of vias should be used to connect this copper pad to one or more larger ground planes on other PCB layers. In split ground systems, it is recommended that this thermal pad be connected to AGND for best performance. The CS42L51 evaluation board demonstrates the op timum thermal pad and via configuration.

CS42L51 to minimize inductance effects . All signals, especially clocks, should be

CS42L51

CS42L51 as pos-

DS679F1 81

10.ADC & DAC DIGITAL FILTERS

Figure 34. ADC Passband Ripple Figure 35. ADC Stopband Rejection

CS42L51

Figure 36. ADC Transition Band Figure 37. ADC Transition Band Detail

Figure 38. DAC Passband Ripple Figure 39. DAC Stopband

Figure 40. DAC Transition Band Figure 41. DAC Transition Band (Detail)

82 DS679F1

11.PARAMETER DEFINITIONS

Dynamic Range

The ratio of the rms value of the signal to the rms sum of all other spectral components over the specified bandwidth. Dynamic Range is a signal-to-noise ratio measurement over the specified band width made with a -60 dBFS signal. 60 dB is added to resulting measurement to refer the measurement to full-scale. This technique ensures that the distortion components ar e below the n oise level an d do n ot affect the m easu rement. This measurement technique has been accepted by the Audio Engineering Society, AES17-1991, and the Electronic Industries Association of Japan, EIAJ CP-307. Expressed in decibels.

Total Harmonic Distortion + Noise

The ratio of the rms value of the signal to the rms sum of all other spectral components over the specified band width (typically 10 Hz to 20 kHz), including distortion components. Expressed in decibels. Measured at -1 and -20 dBFS as suggested in AES17-1991 Annex A.

Frequency Response

A measure of the amplitude response variation from 10 Hz to 20 kHz relative to the amplitude response at 1 k Hz. Units in decibels.

Interchannel Isolation

A measure of crosstalk between the left and right channel pairs. Mea sured for ea ch channel at the co nverter's output with no signal to the input under test and a full-scale signa l applied to the other channel. Units in decibels.

CS42L51

Interchannel Gain Mismatch

The gain difference between left and right channel pairs. Units in decibels.

Gain Error

The deviation from the nominal full-scale analog output for a full-scale digital input.

Gain Drift

The change in gain value with temperature. Units in ppm/°C.

Offset Error

The deviation of the mid-scale transition (111...111 to 000...000) from the ideal. Units in mV.

DS679F1 83

12.PACKAGE DIMENSIONS

32L QFN (5 X 5 mm BODY) PACKAGE DRAWING

CS42L51

e Pin #1 Corner

Pin #1 Corner

Top View

Side View

A1 A

Bottom View

INCHES MILLIMETERS NOTE

DIM MIN NOM MAX MIN NOM MAX

A----0.0394----1.001

A1 0.0000 -- 0.0020 0.00 -- 0.05 1

b 0.0071 0.0091 0.0110 0.18 0.23 0.28 1,2

D 0.1969 BSC 5.00 BSC 1

D2 0.1280 0.1299 0.1319 3.25 3.30 3.35 1

E 0.1969 BSC 5.00 BSC 1

E2 0.1280 0.1299 0.1319 3.25 3.30 3.35 1

e 0.0197 BSC 0.50 BSC 1 L 0.0118 0.0157 0.0197 0.30 0.40 0.50 1

JEDEC #: MO-220

Controlling Dimension is Millimeters.

1. Dimensioning and tolerance per ASME Y 14.5M-1995.

2. Dimensioning lead width applies to the plated terminal and is m easured between 0.20 mm and 0.25 mm from the terminal tip.

THERMAL CHARACTERISTICS

Parameter Symbol Min Typ Max Units

Junction to Ambient Thermal Impedance 2 Layer Board

4 Layer Board

84 DS679F1

52 38

°C/Watt

CS42L51

13.ORDERING INFORMATION

Product Description Package Pb-Free Grade Temp Range Container Order #

Rail CS42L51-CNZ

Tape & Reel CS42L51-CNZR

Rail CS42L51-DNZ

Tape & Reel CS42L51-DNZR

CS42L51

CDB42L51

CRD42L51

Low-Power Stereo

CODEC w/HP Amp for

Portable Apps

CS42L51 Evaluation

Board

CS42L51 Reference

Design

Commercial -10 to +70° C

32L-QFN Yes

Automotive -40 to +85° C

- No - - - CDB42L51

- No - - - CRD42L51

14.REFERENCES

1. Cirrus Logic, AN18: Layout and Design Rules for Data Converters and Other Mixed Signal Devices, Version 6.0, February 1998.

2. Cirrus Logic, Techniques to Measure and Maximize the Performance of a 120 dB, 96 kHz A/D Converter Integrated Circuit, by Steven Harris, Steven Green and Ka Leung. Presented at the 103rd Co nvention of the Audio Engineering Society, September 1997.

3. Cirrus Logic, A Stereo 16-bit Delta-Sigma A/D Conv erter for Digital Audio, by D.R. Welland, B.P. Del Signore, E.J. Swanson, T. Tanaka, K. Hamashita, S. Hara, K. Takasuka. Paper presented at the 85th Convention of the Audio Engineering Society, November 1988.

4. Cirrus Logic, The Effects of Sampling Clock Jitter on Nyquist Sampling Analog-to-Digital Converters, and on Oversampling Delta Sigma ADC's, by Steven Harris. Paper presented at the 87th Convention of the Audio Engineering Society, October 1989.

5. Cirrus Logic, An 18-Bit Dual-Channel Oversampling Delta-Sigma A/D Conver ter, with 19-Bit Mono Applica- tion Example, by Clif Sanchez. Paper presented at the 87th Convention of the Audio Engineering Society, October 1989.

6. Cirrus Logic, How to Achieve Optimum Performance from Delta-Sigma A/D and D/A Converters, by Steven Harris. Presented at the 93rd Convention of the Audio Engineering Society, October 1992.

7. Cirrus Logic, A Fifth-Order Delta-Sigma Modula tor with 110 dB Audio Dynamic Range, by I. Fujimori, K. Hamashita and E.J. Swanson. Paper presented at the 93rd Convention of the Aud io Engineering Society, October 1992.

8. Philips Semiconductor, The I²C-Bus Specification: Version 2.1, January 2000.

http://www.semiconductors.philips.com

DS679F1 85

15.REVISION HISTORY

Revision Changes

Initial Release

Renamed pin 14, FILT1+, to DAC_FILT+ and pin 16, FILT2+, to ADC_FILT+. Added 1.5 µF capacitor recommendation to figu re “Typical Connection Diagram (Software Mode)” on page 10. Removed the 0.1µF capacitors from pins DAC_FILT+, ADC_FILT+ and VQ on the figures “Typical Connection

Diagram (Software Mode)” on page 10 and “Typical Connection Diagram (Hardware Mode)” on page 11.

Added DAC Isolation specific ation to “Analog Input Characteristics (Commercial - CNZ)” on page 13 and “Analog

Input Characteristics (Automotive - DNZ)” on page 14.

Corrected specification table “Headphone Output Power Characteristics” on page 19. Removed t

Added t

page 20.

Adjusted timing specifications t

Specifications - Serial Port” on page 20.

Added MIC Bias PSRR specification to “DC Electrical Characteristics” on page 24. Adjusted specification table “Power Consumption” on page 25. Removed QSM clock ratios 128, 192, 256, 384 and HSM ratios 128, 192 from Table 3 on page 39. Modified Digital Mix description in section “Digital Mix (DIGMIX)” on page 53. Corrected DAC Zero Cross timeout period in section “Zero Cross” on page 59. Adjusted BEEP off time settings in section “Beep Off Time (OFFTIME[2:0])” on page 63. Modified BEEP description in section “Beep (BEEP)” on page 64. Adjusted the minimum settings for the “Noise Gate Boost (NG_BOOST) and Threshold (THRESH[3:0])” on

page 72.

Swapped bits PCMA_OVFL w/PCMB_OVFL and ADCA_OVFL w/ADCB_OVFL in register “Status (Address 20h)

(Read Only)” on page 73.

Corrected Charge Pump Frequency setting in section “Charge Pump Frequency (CHRG_FREQ[3:0])” on

page 74.

Added sections “Headphone THD+N versus Output Power Plots” on page 75 and “ADC_FILT+ Capacitor Effects

on THD+N” on page 78.

timing specification from table in section “Switching Specifications - Serial Port” on page 20.

s(SDO-SK)

and t

h(SK-SDO)

timing specification to table in section “Switching Specifications - Serial Port” on

s(SD-SK)

from 0 ns to 20 ns and th from 50 ns to 20 ns in table in section “Switching

CS42L51

86 DS679F1

Revision Changes

Adjusted the minimum voltage specification in “Specified Operating Conditions” section on page 12. Adjusted Ambient Operating Temp. specification in “Absolute Maximum Ratings” section on page 12. Adjusted maximum “Analog In to PGA to ADC” THD+N performance specification in “Analog Input Characteris-

tics (Commercial - CNZ)” on page 13.

Added Offset Error specification to “Analog Input Characteristics (Commercial - CNZ)” on page 13 and “Analog

Input Characteristics (Automotive - DNZ)” on page 14.

Corrected Interchannel Gain Mismatch specification in “Anal og Input Characteristics (Commercial - CNZ)” on

page 13 and “Analog Input Characteristics (Automotive - DNZ)” on page 14.

Adjusted ADC full scale input voltage specification in “Analog Input Characteristics (Commercial - CNZ)” on

page 13 and “Analog Input Characteristics (Automotive - DNZ)” on page 14.

Corrected Group Delay characteristic in table in section “ADC Digital Filter Characteristics” on page 15.

= 10kΩ” THD+N performance specification in “Analog Output Characteristics (Commer-

from 40 ns to 52 ns and t

d(MSB)

from 1000 ns to 3450 ns in table in section “” on page 21.

ack

PP1

Adjusted maximum “R

cial - CNZ)” on page 16 and “Analog Output Characteristics (Automotive - DNZ)” on page 17.

Corrected Group Delay characteristic in table in section “Combined DAC Interpolation & on-Chip Analog FIlter

Response” on page 20.

Adjusted timing specifications t

“Switching Specifications - Serial Port” on page 20 .

Adjusted I²C timing specification t Adjusted High-Level Input Voltage specifications VIH from 0.65VL to 0.68VL and V

table in section “Digital Interface Specifications & Characteristics” on page 24.

Adjusted the +20 dB Digital Boost block before the ALC feedback path in Figure 8 on page 28. Modified ALC Recommended Settings in section “Automatic Level Control (ALC)” on page 32. Modified step 2 of the “Recommended Power-Down Sequence” on page 42. Corrected default values for ALC and Limiter Release Rates shown in “Register Quick Reference” on page 46. Corrected default value for the DAC_SZC bits and Added AMUTE bit and description in “DAC Control (Address

09h)” on page 58.

Added section “Headphone Amplifier Efficiency” on page 77. Corrected ADC Filter Response shown in Figures 34, 35, 36, and 37 on page 82. Corrected ADC_SNGVOL description in “MIC Control (Address 05h)” on page 53.

Final Release

s(SDO-SK)

CS42L51

from 30 ns to 20 ns in table in section

from 0.35VL to 0.32VL in

DS679F1 87

CS42L51

Contacting Cirrus Logic Support

For all product questions and inquiries, contact a Cirrus Logic Sales Representative. To find the one nearest to you, go to www.cirrus.com.

IMPORTANT NOTICE

Cirrus Logic, Inc. and its subsidiaries ("Cirrus") believe that the information contained in this document is accurate and reliable. However, the information is subject to change without not ice and is pr ovided "AS IS" witho ut warr anty of any kind (express or implied). Customers are advised to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditio ns of sa le supplied at the time of order acknowledgment, including those pertaining to warranty, indemnification, and limitation of liability. No responsibility is assumed by Cirrus for the use of this information, including use of this information as the basis for manufacture or sale of any items, or for infringement of patents or other rights of third parties. This document is the property of Cirrus and by furnishing this information, Cirrus grants no license, express or implied under any patents, mask work rights, copyrights, trademarks, trade secrets or other inte llectual property rig hts. Cirrus owns the copyrights associated with the information contained herein and gives consent for copies to be made of the information only for use within your organization with respect to Cirrus integrated circuits or other products of Cirrus. This consent does not extend to other copying such as copying for general distribution, advertising or promotional purposes, or for creating any work for resale.

CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). CIRRUS PRODUCTS ARE NOT DESIGNED, AUTHORIZED OR WARRANTED FOR USE IN AIRCRAFT SYSTEMS, MILITARY APPLICATIONS, PRODUCTS SURGICALLY IMPLANTED INTO THE BODY, AUTOMOTIVE SAFETY OR SECURITY DEVICES, LIFE SUPPORT PRODUCTS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF CIRRUS PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER’S RISK AND CIRRUS DISCLAIMS AND MAKES NO WARRANTY, EXPRESS, STATUTORY OR IMPLIED, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR PARTICULAR PURPOSE, WITH REGARD TO ANY CIRRUS PRODUCT THAT IS USED IN SUCH A MANNER. IF THE CUSTOMER OR CUSTOMER’S CUSTOMER USES OR PERMITS THE USE OF CIRRUS PRODUCTS IN CRITICAL APPLICATIONS, CUSTOMER AGREES, BY SUCH USE, T O FULLY INDEMNIF Y CIRRUS, ITS OF FICE RS, DI RECTORS, EMPLOYEES, DISTRI BUTORS AND OTHER AGENTS FROM ANY AND ALL LIABILITY, INCLUDING ATTORNEYS’ FEES AND COSTS, THAT MAY RESULT FROM OR ARISE IN CONNECTION WITH THESE USES.

Cirrus Logic, Cirrus, and the Cirrus Logic logo designs are trademarks of Cirrus Logic, Inc. All other brand and product names in this document may be trademarks or service marks of their respective owners.

I²C is a registered trademark of Philips Semiconductor. SPI is a trademark of Motorola, Inc.

88 DS679F1

Cirrus Logic CS42L51 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

1. PIN DESCRIPTIONS - SOFTWARE (HARDWARE) MODE

1.1 Digital I/O Pin Characteristics

Table 1. I/O Power Rails

2. TYPICAL CONNECTION DIAGRAMS

Figure 1. Typical Connection Diagram (Software Mode)

Figure 2. Typical Connection Diagram (Hardware Mode)

3. CHARACTERISTIC AND SPECIFICATION TABLES

SPECIFIED OPERATING CONDITIONS

ABSOLUTE MAXIMUM RATINGS

ANALOG INPUT CHARACTERISTICS (COMMERCIAL - CNZ)

ANALOG INPUT CHARACTERISTICS (AUTOMOTIVE - DNZ)

ANALOG OUTPUT CHARACTERISTICS (COMMERCIAL - CNZ)

ANALOG OUTPUT CHARACTERISTICS (AUTOMOTIVE - DNZ)

LINE OUTPUT VOLTAGE CHARACTERISTICS

HEADPHONE OUTPUT POWER CHARACTERISTICS

Figure 3. Headphone Output Test Load

COMBINED DAC INTERPOLATION & ON-CHIP ANALOG FILTER RESPONSE

SWITCHING SPECIFICATIONS - SERIAL PORT

Figure 4. Serial Audio Interface Slave Mode Timing

Figure 5. Serial Audio Interface Master Mode Timing

SWITCHING CHARACTERISTICS - SPI™ CONTROL PORT

Figure 7. Control Port Timing - SPI Format

DC ELECTRICAL CHARACTERISTICS

DIGITAL INTERFACE SPECIFICATIONS & CHARACTERISTICS

POWER CONSUMPTION

4. APPLICATIONS

4.1 Overview

4.1.1 Architecture

4.1.2 Line & MIC Inputs

4.1.3 Line & Headphone Outputs

4.1.4 Signal Processing Eng ine

4.1.5 Beep Generator

4.1.6 Device Control (Hardware or Software Mode)

4.1.7 Power Management

4.2 Hardware Mode

Table 2. Hardware Mode Feature Summary

4.3 Analog Inputs

Figure 8. Analog Input Architecture

4.3.1 Digital Code, Offset & DC Measurement

4.3.2 High-Pass Filter and DC Offset Calibration

4.3.3 Digital Routing

4.3.4 Differential Inputs

Figure 9. MIC Input Mix w/Common Mode Rejection

Figure 10. Differential Input

4.3.5 Analog Input Multiplexer

4.3.6 MIC & PGA Gain

4.3.7 Automatic Level Control (ALC)

Figure 11. ALC

4.3.8 Noise Gate

Figure 12. Noise Gate Attenuation

4.4 Analog Outputs

4.4.1 De-Emphasis Filter

Figure 13. Output Architecture

4.4.2 Volume Controls

4.4.3 Mono Channel Mixer

Figure 14. De-Emphasis Curve

4.4.4 Beep Generato r

4.4.5 Tone Control

Figure 15. Beep Configuration Options

4.4.6 Limiter

Figure 16. Peak Detect & Limiter

4.4.7 Line-Level Outputs and Filtering

4.4.8 On-Chip Charge Pump

4.5 Serial Port Clocking

4.5.1 Slave

4.5.2 Master

Table 3. MCLK/LRCK Ratios

Figure 17. Master Mode Timing

4.5.3 High-Impedance Digital Output

Figure 18. Tri-State Serial Port

4.5.4 Quarter- and Half-Speed Mode

4.6 Digital Interface Formats

4.7 Initialization

Figure 20. Left-Justified Format

Figure 21. Right-Justified Format (DAC only)

4.8 Recommended Power-Up Sequence