Philips ucb1100 DATASHEETS

INTEGRATED CIRCUITS

UCB1100

Advanced modem/audio analog front-end

Preliminary specification Supersedes data of 1996 Apr 09 Version 1.2

 

1998 May 08

Philips Semiconductors Preliminary specification

UCB1 100Advanced modem/audio analog front-end

Version 1.2

GENERAL DESCRIPTION

The UCB1100 is a single chip, integrated mixed signal audio and telecom codec. The single channel audio codec is designed for direct connection of a microphone and speaker. The built-in telecom codec can directly be connected to a DAA and supports high speed modem protocols. The incorporated 10 bit analogue to digital converter and the touch screen interface provides complete control and readout of a connected 4 wire resistive touch screen. The 10 additional general purpose I/O pins provides programmable inputs and/or outputs to the system.

The UCB1100 has a serial interface bus (SIB) intended to communicate to the system controller. Both the codec input and output data and the control register data is multiplexed on this SIB interface.

APPLICATIONS

•Personal Intelligent Communicators

•Personal Digital Assistants (PDA)

•Screen phones

•Smart Phone and smart Fax

•Intelligent Communicators

KEY FEATURES

•48-pin LQFP (SOT313-2) small body SMD package and low

external component count result in minimal PCB space requirement.

•A 12-bit sigma delta audio codec with programmable sample rate,

input and output voltage levels, capable of connecting directly to speaker and microphone, including digitally controlled mute, loopback and clip detection functions

•A 14-bit sigma delta telecom codec with programmable sample

rate, including digitally controlled input voltage level, mute, loopback and clip detection functions. The telecom codec is intended for direct connection to a DAA (digital access arrangement) and includes a built-in sidetone suppression circuit.

•A complete 4 wire resistive touch screen interface circuit

supporting position, pressure and plate resistance measurements.

•A 10-bit successive approximation ADC with internal track and

hold circuit and analogue multiplier for touch screen readout and monitoring of four external high voltage (7.5V) analogue voltages.

•A high speed, 4 wire serial interface data bus (SIB) for

communication to system controller.

•A 3.3V supply voltage and built in power saving modes make the

UCB1100 optimal for portable and battery powered applications.

T ABLE OF CONTENTS

GENERAL DESCRIPTION 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

APPLICATIONS 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

KEY FEATURES 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TABLE OF CONTENTS 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.0 FUNCTIONAL BLOCK DIAGRAM 3. . . . . . . . . . . . . . . . . . . . .

2.0 ORDERING INFORMATION 4. . . . . . . . . . . . . . . . . . . . . . . . . .

3.0 ABSOLUTE MAXIMUM RATINGS 4. . . . . . . . . . . . . . . . . . . . .

4.0 DC ELECTRICAL CHARACTERISTICS 5. . . . . . . . . . . . . . . .

5.0 PINOUT 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.1 PINLIST 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.0 FUNCTIONAL DESCRIPTION 8. . . . . . . . . . . . . . . . . . . . . . . .

6.1 AUDIO CODEC 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.1.1 AUDIO INPUT SPECIFICATIONS 10. . . . . . . .

6.1.2 AUDIO OUTPUT SPECIFICATIONS 11. . . . . . .

6.2 TELECOM CODEC 12. . . . . . . . . . . . . . . . . . . . . . . . . . .

6.2.1 TELECOM INPUT SPECIFICATIONS 14. . . . .

6.2.2 TELECOM OUTPUT SPECIFICATIONS 15. . .

6.3 TOUCH SCREEN MEASUREMENT MODES 16. . . .

6.3.1 POSITION MEASUREMENT 16. . . . . . . . . . . . .

6.3.2 PRESSURE MEASUREMENT 16. . . . . . . . . . .

6.3.3 PLATE RESISTANCE MEASUREMENT 16. . .

6.4 TOUCH SCREEN INTERFACE 17. . . . . . . . . . . . . . . . .

6.4.1 TOUCH SCREEN SPECIFICATIONS 18. . . . .

6.5 10 BIT ADC. 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.5.1 SPECIFICATION OVERVIEW 21. . . . . . . . . . . .

6.6 ON CHIP REFERENCE CIRCUIT 21. . . . . . . . . . . . . .

6.6.1 SPECIFICATION OVERVIEW 21. . . . . . . . . . . .

6.7 SERIAL INTERFACE BUS 22. . . . . . . . . . . . . . . . . . . . .

6.7.1 SIB DATA FORMAT 23. . . . . . . . . . . . . . . . . . . . .

6.7.2 CODEC DATA TRANSFER 24. . . . . . . . . . . . . .

6.7.3 CONTROL REGISTER DATA TRANSFER 26.

6.7.4 AC ELECTRICAL CHARACTERISTICS 27. . .

6.8 GENERAL PURPOSE I/Os 27. . . . . . . . . . . . . . . . . . . .

6.9 INTERRUPT GENERATION 27. . . . . . . . . . . . . . . . . . .

6.10 RESET CIRCUITRY 28. . . . . . . . . . . . . . . . . . . . . . . . . .

7.0 MISCELLANEOUS 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7.1 POWER ROUTING STRATEGY 29. . . . . . . . . . . . . . . .

8.0 CONTROL REGISTER OVERVIEW 30. . . . . . . . . . . . . . . . . .

9.0 PACKAGE OUTLINES 34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9.1 PACKAGE OUTLINE LQFP48 34. . . . . . . . . . . . . . . . . .

10.0 DEFINITIONS 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1998 May 08

Philips Semiconductors Preliminary specification

UCB1 100Advanced modem/audio analog front-end

1.0 FUNCTIONAL BLOCK DIAGRAM

test

2xVddd2xVssdVdda1Vssa1

audio_input_enable

sibdout

encoder

serial bus

control data registers

to all other analog and digital blocks

noise

digital

filter

digital

decimation

64fs

digital

volume

64fs

sibsync

serial bus

shaper

control

sibclk

controller

serial bus

telecom input enable

audio_output_enable

attn[4,5]

sibdin

digital

decimation

64fs

decoder

filter

fst 64fst

fsa 64fsa

reset

internal

digital

64fs

reset

noise

shaper

nreset

stretcher

sample

frequency

sample

frequency

divider

irqout

clear_interrupt[0:15]

Interrupt

controller

rising_edge_ena[0:15]

interrupt data

from other blocks

divtel0:6]

eanble data

for all

analog blocks

divaud[0:6]

power

control

telecom output enable

voltage

reference

external

filter

falling_edge_ena[0:15]

Programmable IO pin block

IOmode[0:9] IOwdat[0:9] IOrdat[0:9]

adc

start

sync

enable

stop logic

ADC start

to external register 11

10 bit ADC

io0 io1 io2 io3 io4 io5 io6 io7 io8 io9

adc_sync_ena

adcsync

1998 May 08

64fsa

gain[0,2]

loopback

gain[3,4]

micp

mux

1 bit ADC

micgnd

4 bit DAC

AUDIO CODEC

attn[0,3]

vssa1

spkrp

spkrn

vdda2

vssa2

external

reference

64fsa

effect

mute

echo on loopback

side tone suppression

1 bit ADC

attenuation

mux

tinp

TELECOM CODEC

tinn

4 bit DAC

toutp

toutn

effect

mute

vrefbyp

Figure 1. Block Diagram of the UCB1100

bias voltage

touch screen

switch matrix

tspy

tsmx

tsmy

vssa3

mux

switched

ad0

ad1

track & hold

9 to 1

voltage

dividers

ad2

ad3

analog pin

digital pin

SN00126

supply pin

Philips Semiconductors Preliminary specification

UCB1 100Advanced modem/audio analog front-end

2.0 ORDERING INFORMATION

DESCRIPTION

ÁÁÁÁ

ORDERING

БББББ

CODE

Plastic low profile

quad flat package;

ÁÁÁÁ

48 leads

UCB1100LP/X3

БББББ

3.0 ABSOLUTE MAXIMUM RATINGS

SYMBOL PARAMETER MIN MAX UNIT

DDMAX

IMAX

ADMAX

OMAX

IKMAX

OKMAX

OLMAX

stg

NOTES:

1. Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any conditions other than those described in the Absolute Maximum Rating section of this specification is not implied.

2. This product includes circuitry specially designed for the protection of its internal devices from damaging ef fects of excessive static charge. Nonetheless, it is suggested that conventional precautions be taken to avoid submitting the UCB1100 to conditions exceeding the maximum ratings.

3. Parameters are valid over the operating ambient temperature unless otherwise specified. All voltages are with respect to the V unless otherwise noted.

Supply voltage –0.5 5.0 V DC input voltage, except AD0–3 inputs –0.5 VDD+0.5 V DC input voltage AD0–3 inputs –0.5 8.5 V DC output voltage –0.5 VDD+0.5 V DC diode input current, all inputs 10 mA DC diode output current 10 mA Continuous output current, digital outputs 4 mA Storage temperature –55 150 °C

PACKAGE

ÁÁÁ

DRAWING

SOT313-2

ÁÁÁ

SSD

pin,

1998 May 08

Philips Semiconductors Preliminary specification

SYMBOL

PARAMETER

NOTES

UNIT

UCB1 100Advanced modem/audio analog front-end

4.0 DC ELECTRICAL CHARACTERISTICS

= 0°C to 70°C, V

amb

Voltage with respect to the V

DDD

DDA1

DDA2

SSA2

SSA3

DDD

DDA1

DDA2

TSCB

ADFS

TSFS

SIBCLK

amb

NOTES:

1. Indicative value only. Value will be frozen following silicon measurements.

2. Excluding connected touch screen and speaker load currents.

SSD

= V

SSA1

pin, unless otherwise specified.

SSD

SSA2

= V

= 0V , sibclk = 10MHz, audio_divisor = 12, telecom_divisor = 40.

SSA3

LIMITS

MIN TYP MAX

digital supply voltage 3.0 3.3 3.6 V analogue supply voltage (excl.speaker driver) 3.0 3.3 3.6 V analogue supply voltage (speaker driver only) 3.0 3.3 3.6 V analogue ground voltage wrt. V analogue ground voltage wrt V digital supply current,

SSD

Note 1

–0.4 0 0.4 V –0.4 0 0.4 V

full functionality 19 mA only audio codec activated 17 mA only telecom codec activated 19 mA only touch screen activated 15 mA only adc activated 15 mA no functions activated, sibclk stopped 10 µA

analogue supply current,

Note 1, Note 2 full functionality 3.8 mA only audio codec activated 1.5 mA only telecom codec activated 1.7 mA only touch screen activated 0.4 mA only adc activated 0.5 mA no analogue functions activated <10 µA

total speaker driver supply current

Note 1, Note 2 full functionality 0.2 mA only audio codec activated 0.2 mA only telecom codec activated 10 µA only touch screen activated 10 µA only adc activated 10 µA no analogue functions activated 10 µA

touch screen bias voltage 1.8 V maximum touch screen bias current 10 mA full scale voltage ad0–ad3 inputs 7.5 V full scale input touch screen inputs 7.5 V input low voltage –0.5 0.3*V input high voltage 0.7*V

DDD

output low voltage IOL=2mA 0.2*V output high voltage IOH=2mA 0.8*V

DDD

+0.5 V

DDD

V clock frequency 0 10 15 MHz Operating Ambient Temperature 0 70 °C

1998 May 08

Philips Semiconductors Preliminary specification

UCB1 100Advanced modem/audio analog front-end

5.0 PINOUT

vddd

io6

io5

io4

not used

irqout

sibdin

sibclk

sibdout

sibsync

nreset

vssd

adcsync

vssd

not used

vssa2

spkrn sprkp

vdda2

toutp toutn

io7 io8 io9

4847464544434241403938

1 2 3 4 5 6 7 8

9 10 11 12

UCB1100

LQFP48

TOP VIEW

io3

io2

io1

io0

vddd

not used

tspx

tsmy

tsmx

tspy

vssa3

ad0

1314151617181920212223 test

tinn

tinp

vrefbyp

vdda1

vssa1

not used

micgnd

micp

ad3

Figure 2. LQFP48 (SOT313-2)

ad2

24 ad1

SN00127

1998 May 08

Philips Semiconductors Preliminary specification

SYMBOL

PIN TYPE

DESCRIPTION

NOTE

UCB1 100Advanced modem/audio analog front-end

5.1 Pinlist

PINNING

LQFP48

vddd 32, 48 supply digital supply

vssd 5, 37 ground digital ground 1 vdda1 17 supply analogue supply vssa1 18 ground analogue ground 1 vdda2 10 supply analogue speaker driver supply vssa2 7 ground analogue speaker driver ground vssa3 26 ground touch screen switch matrix ground

sibclk 41 CMOS input SIB serial interface master clock

sibdin 42 CMOS input SIB data input

sibdout 40 CMOS output ‘0’ / Hi-Z SIB data output 2

sibsync 39 CMOS input SIB synchronization

irqout 43 CMOS output

micp 21 analogue input Hi-Z microphone signal input

micgnd 20 analogue input Hi-Z microphone ground switch input

sprkp 9 analogue output Hi-Z positive speaker output 3 spkrn 8 analogue output Hi-Z negative speaker output 3

tinp 15 analogue input Hi-Z positive telecom codec input 3

tinn 14 analogue input Hi-Z negative telecom codec input 3 toutp 11 analogue output Hi-Z positive telecom codec output 3 toutn 12 analogue output Hi-Z negative telecom codec output 3

ad0–3 25–22 analogue input Hi-Z analogue high voltage inputs

tspx 30 analogue IO Hi-Z positive X-plate touch screen tsmx 28 analogue IO Hi-Z negative X-plate touch screen

tspy 27 analogue IO Hi-Z positive Y-plate touch screen tsmy 29 analogue IO Hi-Z negative Y-plate touch screen

adcsync 4 digital input adc synchronization pulse input

vrefbyp 16 analogue IO Hi-Z external reference voltage input, external filter connection

io0–9 33–36,

45–47,

1–3

nreset 38 CMOS input

test 13 CMOS input ‘0’ test mode protection 4

not used 6, 19,

31, 44

NOTES:

1. The vssd and vssa1 pins are connected to each other within the UCB1100.

2. The first 64 bits of the sib frame will be ‘0’, the remaining bits in the sib frame will be Hi-Z.

3. The spkrp/spkrn, tinp/tiln and toup/toutn are dif ferential pairs.

4. The test pin contains a internal pull down. This pin should be connected to vssd in normal mode of the UCB1100.

active-High

CMOS IO input general purpose IO pins

active-Low

RESET

STATE

‘0’ interrupt output

asynchronous reset input

not connected pins

1998 May 08

Philips Semiconductors Preliminary specification

UCB1 100Advanced modem/audio analog front-end

6.0 FUNCTIONAL DESCRIPTION

The UCB1100 consists of several analogue and digital sub circuits which can be programmed via the Serial Interface Bus (SIB). This enables the user to set the UCB1100 functionality according actual application requirements.

6.1 Audio codec

The audio codec contains an input channel, built up from a 64 times oversampling sigma delta analogue to digital converter (ADC) with digital decimation filters and a programmable gain microphone preamp. The output path consists of a digital up sample filter, a 64 time oversampling 4 bit digital to analogue converter (DAC) circuit followed by a speaker driver, capable of driving directly a low impedance bridge tied (BTL) speaker. The output path features digitally programmable attenuation and a mute function. The audio codec also incorporates a loopback mode, in which codec output path and the input path are connected in series.

The audio sample rate is derived from the SIB interface clock pin (SIBclk) and is programmable through the SIB interface. The audio sample rate is given by the following equation:

(2 *

Fsibclk

Fsa



micp

micgnd

audio_divisor

(64 *

)

(5 

)

gain[3,4]

audio_divisor

loopback

mux

 128)

gain[0,2]

64fsa

1 bit ADC

For example, a serial clock of 10 MHz, with a divisor of 14, results in an audio sample rate of 22.321kHz. Both the rising and the falling edges of the sibclk are used in case an odd audio_divisor is set. Thus a 50% duty cycle of the sibclk signal is mandatory to obtain time equidistant sampling with odd divisors.

The frequency response of the audio codec depends mainly on the selected sample rate, since the bandwidth is limited in the down and up sampling filters. These digital filters both contain several FIR and IIR low pass filters and a DC removal filter (high pass filter). A 1st order analogue anti aliasing filter is implemented at the input of the microphone input to prevent aliasing in the adc path. A 3rd order smoothing filter is implemented between dac and speaker driver stage to reduce the spurious frequencies at the speaker outputs.

The audio codec input (=ADC) and output (= DAC) paths can be enabled individually by setting the audio_adc and/or audio_dac bits in the audio control register B. These enable bits operate both on the associated analogue and digital functions, for optimal power control of both the analogue and the digital parts.

audio_input_enable

64fs

vdda2

spkrp spkrn

vssa2

vssa1

interpolator

low pass

FIR

loop input

mute

Sinc4

FIR

half band

FIR

loop input

attn[0,3]

removal

round

4 bit DAC

64fsa

half band

WDF

half band

WDF

64fs

Figure 3. Detailed Block Diagram Audio codec

digital

volume

control

attn[4,5]

audio_output_enable

half band

WDF

+3dB

noise

shaper

+3dB

round

removal

SN00128

1998 May 08

Philips Semiconductors Preliminary specification

UCB1 100Advanced modem/audio analog front-end

UCB1100 UCB1100

vdda1

micp

micgnd

vssa1

vdda1

micp

micgnd

vssa1

‘Passive’ Microphone ‘Active’ Microphone

SN00129

Figure 4. Possible Microphone Connections

The UCB1100 audio codec input path accepts microphone signals directly, only a DC blocking capacitor is needed, since the micp input is biased around 1.4V . The ‘ground’ side of the microphone is either connected to the analogue ground (vssa1) or to the micgnd pin of the UCB1100. The latter will decrease the current consumption of active microphones, since the micgnd pin is made Hi-Z when the audio codec input path is disabled.

The full scale input voltage of the audio input path is programmable in 1.5dB steps by setting the appropriate data in the

audio-input-gain

bits in the audio control register A. A clip detection circuit will inform the user whenever the input

voltage exceeds the maximum input voltage. In that case the

detect status

bit in audio control register B is set. An interrupt is

generated on the irqout pin of the UCB1100 whenever the

clip detect rising interrupt

audio edge interrupt

bit is set in the rising edge interrupt enable or falling

or the

enable audio detect falling

clip

enable

edge interrupt control register B is set.

48dB

24dB

digital attenuation

0dB

21dB

analog attenuation

0dB

24dB 48dB 69dB

programmed attenuation

SN00130

Figure 5. Analogue and Digital Attenuation Settings

Audio Output Path

The output level can be attenuated in 3dB steps down to -69dB. The 8 highest attenuation steps are implemented in the analogue circuitry, while the two 24dB steps are implemented in the digital domain. This preserves the ‘audio quality’ of the output signal at lowest attenuation settings. The speaker driver is muted when the

audio-mute

bit in the audio control register B is set. The speaker driver will remain activated in that case, however no signal is produced by the speaker driver circuitry.

UCB1100 UCB1100 UCB1100

spkrp

spkrn

Bridge Tied

spkrp spkrp

spkrn spkrn

Single Ended Speaker Connections

Speaker

Load

SN00131

Figure 6. Possible Speaker Connections

The speaker driver is designed to directly drive a bridge tied load (BTL). This yields the highest output power and it does not require external DC blocking capacitors. The speaker driver also accepts single ended connection of a speaker, in which case the maximum output power is reduced to a quarter of the BTL situation. Consequently this way of connecting the speaker to the speaker driver reduces the power consumption of the speaker driver in the UCB1100 by a factor of 2. Figure 6 shows possible ways to connect a speaker to the UCB1100.

The audio input and output path are activated independently; the input path is enabled when the output path is enabled when the

audio-input-enable

audio-output-enable

bit is set, the

bit is set in the audio control register B. This provides the user the means to reduce the current consumption of the UCB1100 if one part of the audio codec is not used in the application.

The audio codec has a loopback mode for system test purposes, which is activated when the

audio_loopback enable

bit in the audio control register B is set. This is an analogue loopback which internally connects the output of the audio output path to the input of the audio input path, (see Figure 3). In this mode the normal microphone input is ignored, but the speaker driver can be operated normally .

1998 May 08

Philips Semiconductors Preliminary specification

SYMBOL

PARAMETER

CONDITIONS

UNIT

UCB1 100Advanced modem/audio analog front-end

6.1.1 Audio Input Specifications

LIMITS

MIN TYP MAX

INAM

MICP

INPAI

HINE

AGS

EAR

ROES

DNA

THUD

THD

MGAI

SNR

MGAI

RIP

SBR

NOTE: Coding scheme for ADC output data is 2’s complement.

audio sample frequency 26 kHz full scale input voltage 0 dB gain setting 0.28 V

DC bias voltage micp input audio input path enabled 1.4 V input impedance audio input path enabled 25 kΩ impedance micgnd to vssa1 audio input path enabled 100 Ω gain step size 1.3 1.5 1.7 dB number of gain steps 32 maximum gain 46.5 dB

gain error (accuracy of gain setting)

0 dB gain setting,

full scale input voltage

–1 0 1 dB

resolution audio input 12 bit differential non linearity audio input ADC 0.9 LSB

total harmonic distortion

total harmonic distortion signal to noise ratio

audio input signal to noise ratio

pass band ripple F stop band rejection

audio input out of band rejection

audio input

0db input gain selected

0.28Vpp, 1kHz to micp

46.5dB gain setting,

1mVpp, 1kHz to micp

0dB input gain selected

0.28Vpp, 1kHz to micp

46.5dB gain selected

1mVpp, 1kHz to micp

<Fsig < F

PLAI

<Fsig.<20kHz 70 dB

SHAI

PHAI

65 dB

50 dB

0.03 %

0.1 %

0.5 dB

F > 20kHz t.b.f. mVrms

RIP

0dB

SBR

PLA

FREQUENCY (Hz)

Figure 7. Audio Input Path Frequency Response

1998 May 08

= 0.00016 * F

PLA

= 0.42 * F

PHA

= 0.6 * F

SHA

PHA

SN00132

Philips Semiconductors Preliminary specification

SYMBOL

PARAMETER

CONDITIONS

UNIT

UCB1 100Advanced modem/audio analog front-end

6.1.2 Audio Output Specifications

LIMITS

MIN TYP MAX

OFFIA

OOA

OFFOA

SPK

SOA

NSOA number of attenuation steps 24

MOA

ROES

DNA

THUD

OAS

THUD

OAH

SNR

OAS

SNR

OAH

RIP

SUOA

SBR

IOA

SPKR

NOTE: Coding scheme for DAC input data is 2’s complement.

offset error No signal applied to micp 0 LSB

0dB attenuation,

full scale output voltage

offset error 16ohm speaker 50 mV DC bias voltage

spkrp and spkrn pin

16ohm speaker

3.2 V

differential Spkrp–Spkrn

Audio output path enabled 1.4 V

attenuation step size 2.8 3.0 3.2 dB

maximum attenuation 69 dB resolution 12 bit differential non linearity DAC 0.9 LSB total harmonic distortion

16Ω speaker total harmonic distortion

1kΩ headphone signal to noise ratio

16Ω speaker signal to noise ratio,

1kHΩ headphone pass band ripple F cut off frequency upper stop band 0.6 F stop band rejection F

0dB attenuation

20Hz to 20kHz

0dB attenuation

20Hz to 20kHz bandwidth

0dB attenuation

20Hz to 20kHz bandwidth

0dB attenuation

20Hz to 20kHz bandwidth

< Fsig <– F

PLAO

<Fsig.<20kHz 70 dB

SHAO

PHAO

0.5 2 %

0.03 %

40 80 dB

65 80 dB

0.5 dB

integrated out of band energy F > 20kHz 30 mVrms speaker impedance 8 16 Ω

RIP

0dB

SBR

PLA

FREQUENCY (Hz)

Figure 8. Audio Output Filter Frequency Response

1998 May 08

PHA

SHA

SN00133

= 0.00016 * F F F

PLA PHA SHA

= 0.42 * F = 0.6 * F

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