Cirrus Logic CS5451-BS Datasheet

CS5451
Six-Channel Delta-Sigma Analog-to-Digital Converter

Features

l Synchronous Sampling l On-chip 1.2 V Reference (25 ppm/°C typ) l Power Supply Configurations:
VA+ = +3 V; VA- = -2 V; VD+ = +3 VSupply tolerances ±10%
l Power Consumption
20 mW Typical at VD+ = +3 V
l Simple Four-wire Serial Interface l Charge Pump Driver output generates
negative power supply.
l Ground-Referenced Bipolar Inputs
VA+
GAIN IIN1+ IIN1-
VIN1+ VIN1-
x1, 20
x1
4th Order∆ΣModulator
2nd Order∆ΣModulator

Description

The CS5451 is a highly integrated Delta-Sigma (∆Σ) An­alog-to-Digital Converter (ADC) developed for the Power Measurement Industry. The CS5451 combines six ∆Σ ADCs, decimation filters, and a serial interface on a sin­gle chip. The CS5451 interfaces directly to a current transformer or shunt to measure current, and resistive divider or transformer to measure voltage. The product features a serial interface for communication with a mi­cro-controller or DSP. The product is initialized and fully functional upon reset, and includes a Voltage Reference.
ORDERING INFORMATION:
CS5451-BS -40°C to +85°C 28-pin SSOP
RESET
Decimation Filter
Decimation Filter
VD+
IIN2+ IIN2-
VIN2+ VIN2-
IIN3+
IIN3-
VIN3+ VIN3-
VREFIN
VREFOUT
x1, 20
x1
x1, 20
x1
x1
Voltage
Refe ren ce
4th Order∆ΣModulator
2nd Order∆ΣModulator
4th Order∆ΣModulator
2nd Order∆ΣModulator
AGND
Preliminary Product Information
P.O. Box 17847, Austin, Texas 78760 (512) 445 7222 FAX: (512) 445 7581 http://www.cirrus.com
VA-
Decimation Filter
Decimation Filter
Decimation Filter
Decimation Filter
CLOCK
XIN
Serial
Interface
Pulse Output
Regulator
DGND
SE
OWRS
SDO
FSO
SCLK
CPD
This document contains information for a new product. Cirrus Logic reserves the right to modify this product without notice.
Copyright Cirrus Logic, Inc. 2000
(All Rights Reserved)
DS458PP4
JUL ‘01
1
TABLE OF CONTENTS
1. CHARACTERISTICS AND SPECIFICATIONS ........................................................................ 3
ANALOG CHARACTERISTICS ................................................................................................ 3
ANALOG CHARACTERISITCS ................................................................................................ 4
DIGITAL CHARACTERISTICS ................................................................................................. 4
RECOMMENDED OPERATING CONDITIONS ....................................................................... 5
ABSOLUTE MAXIMUM RATINGS ........................................................................................... 5
SWITCHING CHARACTERISTICS .......................................................................................... 6
2. GENERAL DESCRIPTION ....................................................................................................... 7
2.1 Theory of Operation ........................................................................................................... 7
2.2 Performing Measurements ................................................................................................. 8
2.3 High Rate Digital Filters ..................................................................................................... 8
2.4 Serial Interface ................................................................................................................... 8
2.5 System Initialization ........................................................................................................... 9
2.6 Analog Inputs ..................................................................................................................... 9
2.7 Voltage Reference ............................................................................................................. 9
2.8 Power Supply ..................................................................................................................... 9
2.9 PCB Layout ...................................................................................................................... 10
3. PIN DESCRIPTION ................................................................................................................. 11
4. PACKAGE DIMENSIONS........................................................................................................ 13
CS5451
LIST OF FIGURES
Figure 1. Serial Port Timing............................................................................................................. 6
Figure 2. Typical Connection Diagram ............................................................................................7
Figure 3. Serial Port Data Transfer ................................................................................................. 8
Figure 4. Close-up of One Data Frame ........................................................................................... 9
Figure 5. Generating VA- with a Charge Pump ............................................................................. 10
Contacting Cirrus Logic Support For a complete listing of Direct Sales, Distributor, and Sales Representative contacts, visit the Cirrus Logic web site at:
http://www.cirrus.com/corporate/contacts/
Preliminary product information describes products which are in production, but for which full characterization data is not yet available. Advance product infor­mation describes products which are in development and subject to development changes. Cirrus Logic, Inc. has made best efforts to ensure that the information contained in this document is accurate and reliable. However, the information is subject to change without notice and is provided AS IS without warranty of any kind (express or implied). No responsibility is assumed by Cirrus Logic, Inc. for the use of this information, nor for infringements of patents or other rights of third parties. This document is the property of Cirrus Logic, Inc. and implies no license under patents, copyrights, trademarks, or trade secrets. No part of this publication may be copied, reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photographic, or otherwise) without the prior written consent of Cirrus Logic, Inc. Items from any Cirrus Logic website or disk may be printed for use by the user. However, no part of the printout or electronic files may be copied, reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photographic, or otherwise) without the prior written consent of Cirrus Logic, Inc.Furthermore, no part of this publication may be used as a basis for manufacture or sale of any items without the prior written consent of Cirrus Logic, Inc. The names of products of Cirrus Logic, Inc. or other vendors and suppliers appearing in this document may be trademarks or service marks of their respective owners which may be registered in some jurisdictions. A list of Cirrus Logic, Inc. trade­marks and service marks can be found at http://www.cirrus.com.
2 DS458PP4

1. CHARACTERISTICS AND SPECIFICATIONS

CS5451

ANALOG CHARACTERISTICS (T

= -40 °C to +85 °C; +2.7V < VA+ < +3.5V; +2.7V < VD+ < +3.5V;
A
VA- = -2 V ±10%; External VREF+ = 1.2 V; XIN = 4.000 MHz; AGND, DGND = 0.0V.)(See Notes 1 and 2)
Parameter Symbol Min Typ Max Unit
Accuracy (All Channels)
Total Harmonic Distortion THD 74 - - dB
Common Mode Rejection (DC, 50, 60 Hz) CMRR 80 - - dB
Common Mode + Signal on Input VA- - VA+ V
Input Sampling Rate - XIN/4 - Hz
Analog Inputs (Current Channels)
Differential Input Voltage Range Gain=20 [ For example: (v
IIN1+) - (vIIN1-) ] Gain=1
Bipolar Offset Gain=20
Gain=1
IIN -
VOS VOS
±40
-
-
-
±800
0.500 10
1
20
-
-
mV mV
mV mV
Crosstalk (Channel-to-Channel) (50, 60 Hz) - - -120 dB
Input Capacitance Gain = 20
Gain = 1ICIC
-
-
-
-
20
1
pF pF
Effective Input Impedance (Note 3)
Gain=20
Gain=1
EII EII
50
-
-
500
-
600
k k
Noise (Referred to Input) 0-60 Hz Gain=20
Gain=1
0-1 kHz Gain=20
Gain=1
0-2 kHz Gain=20
Gain=1
-
-
-
-
-
-
-
-
-
-
-
-
1
20
2.5 50
3.75 75
µV µV µV µV µV µV
Analog Inputs (Voltage Channels)
Differential Input Voltage Range [ For example: (v
VIN1+) - (vVIN1-) ]
VIN - ±800 - mV
Bipolar Offset Gain=1 VOS - 20 25 mV
Crosstalk to any other channel at full-scale (50, 60 Hz) - - -120 dB
Input Capacitance IC - - 0.2 pF Effective Input Impedance (Note 3) EII - 3 4 M
Noise (Referred to Input) 0-60 Hz 0-1 kHz 0-2 kHz
-
-
-
-
-
-
20 50 75
µV µV µV
Dynamic Characteristics
High Rate Filter Output Word Rate OWRS = “0”
OWRS = “1”
OWR OWR
-
-
XIN/2048 XIN/1024
-
-
Hz Hz
rms
rms
rms
rms
rms
rms
rms
rms
rms
Notes: 1. Specifications guaranteed by design, characterization, and/or test.
2. Analog signals are relative to AGND and digital signals to DGND unless otherwise noted.
3. Effective Input Impedance (EII) varies with clock frequency (XIN) and Input Capacitance (IC) EII = 1/(IC*XIN/4)
DS458PP4 3
CS5451

ANALOG CHARACTERISITCS (continued)

Parameter Symbol Min Typ Max Unit
Reference Output
Output Voltage REFOUT 1.15 - 1.25 V
Temperature Coefficient - 20 50 ppm/°C Load Regulation (Output Current 1µA Source or Sink) ∆V
R
Power Supply Rejection PSRR 60 - - dB
Reference Input
Input Voltage Range VREF+ 1.15 1.2 1.25 V
Input Capacitance - - 10 pF
Input CVF Current - - 1 µA
Power Supplies
Power Supply Currents I
I
A+
D+
PSCA PSCD
Power Consumption (Note 4) PC - - 27 mW
Power Supply Rejection (DC) (see Note 5) (50, 60 Hz)
PSRR PSRR
-610mV
-
-
50 60
-
-
-
-
3 4
-
-
mA mA
dB dB
Notes: 4. All outputs unloaded. All inputs CMOS level.
5. Definition for PSRR: VREFIN tied to VREFOUT, VA+ = VD+ = 3V, AGND = DGND = 0V, VA- = -2V (using charge-pump circuit with CPD). In addition, a 106.07 mV rms (60 Hz) sinewave is imposed onto the VA+ and VD+ pins. The “+” and “-” input pins of both input channels are shorted to VA-. 2048 instantaneous digital output data words are collected for the channel under test. The rms value of the digital sinusoidal output signal is calculated, and this rms value is converted into the rms value of the sinusoidal voltage (measured in mV) that would need to be applied at the channels inputs, in order to cause the same digital sinusoidal output. This voltage is then defined as Veq. PSRR is then (in dB):

106.07
------------- ---
log=

V
eq


DIGITAL CHARACTERISTICS (T

PSRR 20
= -40 °C to +85 °C; +2.7V < VA+ < +3.5V; +2.7V < VD+ < +3.5V;
A
VA- = -2 V ±10%; AGND, DGND = 0.0 V) (See Note 6)
Parameter Symbol Min Typ Max Unit
High-Level Input Voltage V
Low-Level Input Voltage V
High-Level Output Voltage I
Low-Level Output Voltage I
= -5.0 mA V
out
= 5.0 mA V
out
Input Leakage Current (Note 7) I
3-State Leakage Current I
Digital Output Pin Capacitance C
OH
OL
in
OZ
out
IH
0.6 VD+ - VD+ V
IL
0.0 - 0.8 V
(VD+) - 1.0 - - V
--0.4V
1±10µA
--±10µA
-9-pF
Notes: 6. All measurements performed under static conditions.
7. For OWRS and GAIN
pins, input leakage current is 30 µA (Max).
4 DS458PP4
CS5451

RECOMMENDED OPERATING CONDITIONS (AGND, DGND = 0.0 V)

Parameter Symbol Min Typ Max Unit
DC Power Supplies Positive Digital
Positive Analog
Negative Analog
Voltage Reference Input VREF+ - 1.2 - V

ABSOLUTE MAXIMUM RATINGS (AGND, DGND = 0.0 V; See Note 8.)

Parameter Symbol Min Typ Max Unit
DC Power Supplies Positive Digital
Positive Analog
Negative Analog
Input Current, Any Pin Except Supplies (Note 9 and 10) I
Output Current I
Power Dissipation (Note 11) PDN - - 500 mW
Analog Input Voltage All Analog Pins V
Digital Input Voltage All Digital Pins V
Ambient Operating Temperature T
Storage Temperature T
VD+
VA+
VA-
VD+
VA+
VA-
IN
OUT
INA
IND
A
stg
2.7
2.7
-2.2
-0.3
-0.3
-2.5
--±10mA
--±25mA
VA- - 0.3 - (VA+) + 0.3 V
-0.3 - (VD+) + 0.3 V
-40 - 85 °C
-65 - 150 °C
3.0
3.0
-2.0
-
-
3.5
3.5
-1.8
+3.5 +3.5
-0.3
V V V
V V V
Notes: 8. All voltages with respect to AGND.
9. Applies to all pins including continuous over-voltage conditions at the analog input (AIN) pins.
10. Transient current of up to 100 mA will not cause SCR latch-up. Maximum input current for a power supply pin is ±50 mA.
11. Total power dissipation, including all input currents and output currents.
WARNING: Operation at or beyond these limits may result in permanent damage to the device.
Normal operation is not guaranteed at these extremes.
DS458PP4 5
CS5451

SWITCHING CHARACTERISTICS (T

= -40 °C to +85 °C; VA+, VD+ = 3.0 V ±10%; VA- = -2 V
A
±10%; DGND = AGND = 0.0 V; Logic Levels: Logic 0 = 0.0 V, Logic 1 = VD+; CL = 50pF))
Parameter Symbol Min Typ Max Unit
Master Clock Frequency (Note 12) XIN 3 4.000 5 MHz
Master Clock Duty Cycle - 40 - 60 %
Rise Times Any Digital Input (Note 13)
Any Digital Output
Fall Times Any Digital Input (Note 13)
Any Digital Output
t
rise
t
fall
-
-
-
-
50
50
-
-
1.0
1.0
µs
-
ns
µs
-
ns
Serial Port Timing
Serial Clock Frequency (Note 12)
OWRS = “0” OWRS = “1”
Serial Clock Pulse Width High (Note 12)
Pulse Width Low (Note 10)
SCLK falling to New Data Bit t
FSO Falling to SCLK Rising Delay (Note 12) t
FSO Pulse Width (Note 12) t
SE Rising to Output Enabled t
SE Falling to Output in Tri-state t
SCLK SCLK
t
1
t
2
3
4
5
6
7
-
-
-
-
500
1000
0.5
0.5
-
-
-
-
kHz kHz
SCLK SCLK
- - 50 ns
-0.5-SCLK
-1-SCLK
- - 50 ns
- - 50 ns
Notes: 12. Device parameters are specified with a 4.000 MHz clock, OWRS = 1.
13. Specified using 10% and 90% points on wave-form of interest. Output loaded with 50 pF.
SDO
SCLK
FSO
SE
t
5
t
6
MSB(V1) MSB(V1) - 1 LSB(I3)
t
3
t
t
1
2
t
4
t
6

Figure 1. Serial Port Timing

6 DS458PP4
CS5451

2. GENERAL DESCRIPTION

The CS5451 is designed for 3-phase power meter applications and interfaces to a current transform­ers or shunt to measure current, and a resistive di­vider or transformer to measure voltage.
The CS5451 combines six ∆Σ modulators and dec­imation filters, three channels assigned for current input that have programmable input gain amplifi­ers, and three channels assigned for voltage input.
The CS5451 includes six decimation filters that output data at a 2000 Hz or 4000 Hz output word rate (OWR) when the input frequency at XIN =
4.096 MHz.
+3 V
The device outputs data on a serial output port.

2.1 Theory of Operation

The CS5451 is designed to operate from a single +3V supply and provides a ±40 mV and ±800 mV input range for the current channels and ±800 mV range for the voltage channels. These voltages rep­resent the maximum zero-to-peak voltage levels that can be presented to the inputs. The CS5451 is designed to accommodate common mode + signal levels from VA- to VA+. Figure 2 illustrates the CS5451 typical inputs and power supply connec­tions.
VA+
REFIN
VD+
V
PHASE
I
PHASE
Optional External
Reference
+
1.2 V
-2 V
REFOUT
VIN1+, VIN2+, or VIN3+
VIN1-, VI N2-, or VIN3-
IIN1+, IIN2+, or IIN3+
NOTE:
Current input channels
actually measure voltage.
IIN1-, IIN2-, or IIN3-
AGND
VA-
DGND

Figure 2. Typical Connection Diagram

DS458PP4 7
CS5451

2.2 Performing Measurements

The converter outputs are transferred in 16-bit signed (two’s complement) data formats as a per­centage of full scale. Table 1 below illustrates the ideal relationship between the differential voltage presented any one of the input channels and the corresponding output code. Note that for the cur­rent channels, the state of the GAIN input pin is as­sumed to driven low such that the PGA gain on the current channels is 1x. If the PGA gain of the cur­rent channels is set to 20x, a +40 mV differential voltage is presented across any pair of “IINk+” and “IINk-” pins (k = 1, 2, 3) would cause a (nominal) output code of 32767.
Differential Input
Voltage (mV)
+800 7FFF 32767
0.0122 to 0.0366 0001 1
-0.0122 to 0.0122 0000 0
-0.0122 to -0.0366 FFFF -1
-800 8000 -32768
Table 1. Nominal Relationship for Differential Input
Voltage vs. Output Code, for all channels. (Assume PGA
Output Code
(hexadecimal)
gain is set to 1x.)
Output Code
(decimal)

2.3 High Rate Digital Filters

If the OWRS pin is set to logic low, the high-rate filters are implemented as fixed sinc3 filters with the following transfer function:
3
256
1z
1
Hz()

1z
--------------- -------
=
 
This filter samples the modulator bit stream at XIN/8 Hz and decimates to XIN/2048 Hz.
If the OWRS pin is set to logic high, then the trans­fer function is
3
128
1z
1
Hz()

1z
--------------- -------
=
 
The above filter samples the modulator bit stream at XIN/8 Hz and decimates to XIN/1024 Hz.

2.4 Serial Interface

The CS5451 communicates with a target device via a master serial data output port. Output data is pro­vided on the SDO output synchronous with the SCLK output. A third output, FSO, is a framing signal used to signal the start of output data. These three outputs will be driven as long as the SE (serial
SCLK
96 SCLKs
FSO
Each data segment
is 16 bits long.
SDO
Channel 1 V
Channel 1 I
Channel 2 V
8 DS458PP4
Channel 2 I
Channel 3 I
Channel 3 V

Figure 3. Serial Port Data Transfer

SCLK
96 SCLKs
. . .
CS5451
. . .
FSO
3
012
151413 12 11 10 9 8 7654321

Figure 4. Close-up of One Data Frame

SDO
[ Undefined ]
12151413
1011
Channel 1 ( V )
enable) input is held high. Otherwise, these outputs will be high impedance.
Data out (SDO) changes as a result of SCLK fall­ing, and always outputs valid data with SCLK ris­ing. When data is being transferred, the SCLK frequency is either 1/8 of the XIN input frequency (when OWRS is held low) or 1/4 of the XIN input frequency (when OWRS is held high). Any other time, SCLK is held low. (See Figures 3 and 4.)
The framing signal (FSO) output is normally low, but produces a high level pulse lasting one SCLK period when the instantaneous voltage/current data samples are about to be transmitted out of the serial interface (after each A/D conversion cycle). Note: SCLK is not active during FSO high.
For 96 SCLK periods after FSO falls, SCLK is ac­tive and SDO produces valid output. Six channels of 16 bit data are output, MSB first. Voltage and current measurements are output (in that order) for three phases. SCLK will then be held low until the next sample period.

2.5 System Initialization

When power to the CS5451 is applied, the chip must be held in a reset condition using the RESET input.
A hardware reset is initiated when the RESET pin is forced low with a minimum pulse width of 50 ns.
. . .
01514
. . .
0123456789
. . .
Channel 1 (I )
... ... ...
Ch. 2 ( V ) Ch. 2 ( I )
Ch. 3 ( V ) Ch. 3 ( I )
[ Undefined ]

2.6 Analog Inputs

The analog inputs of the CS5451 are bipolar volt­age inputs: Three voltage channel inputs VIN(1-3) and three current channel inputs IIN(1-3). The CS5451 accommodates a full scale range of
±40 mV or ±800 mV on the Current Channels and ±800 mV on the Voltage Channels.

2.7 Voltage Reference

The CS5451 is specified for operation with a +1.2 V reference between the VREFIN and AGND pins. The converter includes an internal 1.2 V reference (50 ppm/°C drift) that can be used by connecting the VREFOUT pin to the VREFIN pin of the de­vice. If higher accuracy/stability is required, an ex­ternal reference can be used.

2.8 Power Supply

The low, stable analog power consumption and su­perior supply rejection of the CS5451 allow for the use of a simple charge-pump negative supply gen­erator. The use of a negative supply alleviates the need for level shifting of the analog inputs. The CPD pin and capacitor C1 provide the necessary analog supply current as shown in Figure 5. The Schottky diodes D1 and D2 are chosen for their low forward voltages and high-speed capabilities. The capacitor C2 provides the required charge storage and bypassing of the negative supply. The CPD output signal provides the charge pump driver sig-
. . .
. . .
DS458PP4 9
CS5451
AGND
BAT 85
D1
C1
40 nF
C2
CPD
VA-
BAT 85
1µF
D2

Figure 5. Generating VA- with a Charge Pump

nal. The frequency of the charge pump driver sig­nal is synchronous to XIN. The nominal average frequency is 1 Mhz. The level on the VA- pin is fed back internally so that the CPD output will regulate the VA- level to -2/3 of VA+ level.
Note the value of C1 in Figure 5. The 40 nF value is recommended when the input frequency present­ed to the XIN pin is 4.00 MHz. If the user decides to use an XIN frequency that is significantly differ­ent than 4.00 MHz (if the XIN frequency is in­creased/decreased by more than 5% of 4.00 MHz, then it is recommended that the user should alter the value of C1. The percentage change in the value of C1 (with respect to a reference value of 40 nF) should be inversely proportional to the percentage change in the XIN frequency. For example, if the XIN frequency is increased from 4.00 MHz to 4.5 MHz, this represents a percentage increase of
12.5%. Therefore, the value of C1 should be re­duced by 12.5%, making the new value for C1 to be 35 nF. For more information about the operation of this type of charge pump circuit, the reader can re­fer to Cirrus Logic, Inc.s application note AN152:
Using the CS5521/24/28, and CS5525/26 Charge Pump Drive for External Loads.

2.9 PCB Layout

For optimal performance, the CS5460A should be placed entirely over an analog ground plane with both the VA- and DGND pins of the device con­nected to the analog plane. Place the analog-digital plane split immediately adjacent to the digital por­tion of the chip.
Note: Refer to the CDB5460A Evaluation Board for
suggested layout details and Applications Note 18 for more detailed layout guidelines. Before layout, please call for our Free Schematic Review Service.
10 DS458PP4

3. PIN DESCRIPTION

CS5451
Serial Clock Output SCLK VD+ Digital Supply
Serial Data Output SDO DGND Digital Ground
Frame Sync FSO CPD Charge Pump Drive
Serial Port Enable SE XIN Master Clock
Current Input Gain GAIN RESET Reset
Analog Ground AGND OWRS Output Word Rate Select
Reference Input VREFIN VIN1+ Differential Voltage Input 1
Reference Output VREFOUT VIN1- Differential Voltage Input 1
Positive Analog Supply VA+ IIN1+ Differential Current Input 1
Negative Analog Supply VA- IIN1- Differential Current Input 1 Differential Voltage Input 3 VIN3+ VIN2+ Differential Voltage Input 2 Differential Voltage Input 3 VIN3- VIN2- Differential Voltage Input 2 Differential Current Input 3 IIN3+ IIN2+ Differential Current Input 2 Differential Current Input 3 IIN3- IIN2- Differential Current Input 2

Clock Generator

XIN - Master Clock Input

Control Pins and Serial Data I/O

1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15

SE - Serial Port Enable

When SE is low, the output pins of the serial port are 3-stated.

SDO - Serial Port Output

Data will be at a rate determined by SCLK.

FSO - Frame Signal Output

Framing signal output for data transfer from SDO pin.

SCLK - Serial Clock Output

A clock signal on this pin determines the output rate of data for SDO pin. Rate of SCLK is determined by XIN frequency and state of OWRS input pin.

RESET - Reset

When reset is taken low, all internal registers are set to their default states.

GAIN - Input Gain Control

Sets input gain for current channels. A logic high sets internal gain to 1, a logic low level sets the gain to 20. If no connection is made to this pin, it will default to logic low level (through internal 200K resistor to DGND).

OWRS - Output Word Rate Select

When OWRS is set to logic low, the output word rate (OWR) at SDO pin is XIN/2048 (Hz). When set to logic high, the OWR at SDO pin is XIN/1024 (Hz). If no connection is made to this pin, then OWRS will default to logic low level (through internal 200K resistor to DGND).
DS458PP4 11

Measurement and Reference Input

IIN(1-3)+, IIN(1-3)- - Differential Current Inputs

Differential analog input pins for current channels.

VIN(1-3)+, VIN(1-3)- - Differential Voltage Inputs

Differential analog input pins for voltage channels.

VREFOUT - Voltage Reference Output

The on-chip voltage reference is output from this pin. The voltage reference has a nominal magnitude of
1.2 V and is referenced to the AGND pin on the converter.

VREFIN - Voltage Reference Input

The voltage input to this pin establishes the voltage reference for the on-chip modulator.

Power Supply Connections

VA+ - Positive Analog Supply

The positive analog supply is nominally +3 V ±10% relative to AGND.
CS5451

VA- - Negative Analog Supply

The negative analog supply is nominally -2 V ±10% relative to AGND.

AGND - Analog Ground

The analog ground pin for input signals.

VD+ - Positive Digital Supply

The positive digital supply is nominally +3 V ±10% relative to DGND.

DGND - Digital Ground

The digital ground is typically at the same level as AGND.

CPD - Charge Pump Drive

This output pin drives the external charge pump circuitry to create a negative supply voltage.
12 DS458PP4

4. PACKAGE DIMENSIONS

28L SSOP PACKAGE DRAWING
N
CS5451
D
E
A2
A
E1
1
2
b
SIDE VIEW
1
23
e
TOP VIEW
INCHES MILLIMETERS NOTE
DIM MIN NOM MAX MIN NOM MAX
A -- -- 0.084 -- -- 2.13 A1 0.002 0.006 0.010 0.05 0.13 0.25 A2 0.064 0.069 0.074 1.62 1.75 1.88
b 0.009 -- 0.015 0.22 -- 0.38 2,3
D 0.390 0.4015 0.413 9.90 10.20 10.50 1
E 0.291 0.307 0.323 7.40 7.80 8.20 E1 0.197 0.209 0.220 5.00 5.30 5.60 1
e 0.022 0.026 0.030 0.55 0.65 0.75
L 0.025 0.0354 0.041 0.63 0.90 1.03
A1
SEATING
PLANE
L
END VIEW
0° 4° 8° 0° 4° 8°
JEDEC #: MO-150
Notes: 1. “D” and “E1” are reference datums and do not included mold flash or protrusions, but do include mold
mismatch and are measured at the parting line, mold flash or protrusions shall not exceed 0.20 mm per side.
2. Dimension “b” does not include dambar protrusion/intrusion. Allowable dambar protrusion shall be
0.13 mm total in excess of “b” dimension at maximum material condition. Dambar intrusion shall not reduce dimension “b” by more than 0.07 mm at least material condition.
3. These dimensions apply to the flat section of the lead between 0.10 and 0.25 mm from lead tips.
DS458PP4 13
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