Preliminary Product Information
This document contains information for a new product.
Cirrus Logic reserves the right to modify this product without notice.
1
Copyright
Cirrus Logic, Inc. 1997
(All Rights Reserved)
Cirrus Logic, Inc.
Crystal Semiconductor Products Division
P.O. Box 17847, Austin, Texas 78760
(512) 445 7222 FAX: (512) 445 7581
http://www.crystal.com
CS5396
CS5397
120 dB, 96 kHz Audio A/D Converter
Features
l24-Bit Conversion
l120 dB Dynamic Range (A -Weighted)
lLow Noise a nd Distortion
>105 dB THD + N
lComplete CMOS Stereo A/D System
Delta-Sigma A/D Converters
Digital Anti-Alias Filtering
S/H Circuitry and Voltage Reference
lCS5396 - digital filter o ptimized for aud i o
lCS5397 - non-aliasing digi tal filter
lAdjustable System Sampling Rates
including 32, 44.1, 48 & 96 kHz
lDifferential Analog Architecture
lLinear Phase Digital Anti-Alias Filtering
l10 Tap Programmable Psychoacoustic Noise
Shaping Filter
lSingle +5 V Power Supply
General Description
The CS5396 and CS5397 are complete analog-to-digital
converters for stereo digital audio systems. They per-
form sampling, analog-to-digital conversion and anti-
alias filtering, generating 24-bit values for both left and
right in puts i n serial form a t sampl e rate s up to 1 00 kHz
per channel.
The CS5396/97 use a patented 7th-order, tri-level delta-
sigma modulator followed by digital filtering and decima-
tion, which removes the need for an external anti-alias
filter. The ADCs use a differential architecture which pro-
vides excellent noise rejection.
The CS5396 has a linear phase filter optimized for audio
applications with ±0.005 dB passband ripple and
>117 dB stopband rejection. The CS5397 has a non-
aliasi ng filte r res po nse with ±0.005 passb and rippl e an d
>117 dB stopba nd atte nuatio n. Oth er feat ures a vailabl e
in both the CS5396 and CS5397 are an optional low
group delay filter and a unique psychoacoustic noise
shaping filter which subjectively truncates the output to
16, 18 or 20 bits while 24-bit sound quality is preserved.
The CS5396/97 are targeted for the highest perfor-
mance professional audio systems requiring wide
dynamic range, negligible distortion and low noise.
ORDERING INFORMATION
CS5396-KS -10° to 50° C 28-pin SOIC
CS5397-KS -10° to 50° C 28-pin SOIC
CDB5396/97 Evaluation Board
Voltage Reference Serial Output Interface
Psychoacoustic
Digital Decimation
LP Filter
DAC
-
+
-
+
S/H
LP Filter
DAC
-
+
-
+
S/H
AINR+
VA
SCLK SDATA1 MCLKD
CS
VCOM MCLKA LRCKADCTL
LGND TST0
AINR-
Comparator
Comparator
AINL+
AINL-
VREF CDIN
CCLK
AGND1 AGND2 AGND0 VL TST1 VD DGND
Calibration
Microcontroller Calibration
SRAM
DACTL
Filter
Filter
(with Low Group
Delay Options )
Digital Decimation
Filter
(with Low Group
Delay Options )
Serial
Control
Port
CAL SDATA2
SEP ‘97
DS229PP2
CS5396 CS5397
2DS229PP2
TABLE OF CONTENTS
TABLE OF CONTENTS .......................................................................................................2
ANALOG CHARACTERISTICS ..........................................................................................4
DIGITAL FILTER CHARACTERISTICS..............................................................................5
POWER AND THERMAL CHARACTERISTICS.................................................................6
DIGITAL CHARACTERISTICS............................................................................................6
ABSOLUTE MAXIMUM RATINGS......................................................................................6
RECOMMENDED OPERATING CONDITIONS ..................................................................7
SWITCHING CHARACTERISTICS .....................................................................................7
SPI CONTROL PORT SWITCHING CHARACTERISTICS........................... ...... ..... ...... .....9
I2C CONTROL PORT SWITCHING CHARACTERISTICS...............................................10
GENERAL DESCRIPTION ...............................................................................................12
Stand-Alone vs. Control Port Mode ........................................................................12
STAND-ALONE MODE ....................................................................................................12
Master Clock - Stand-Alone Mode ..........................................................................12
Serial Data Interface - Stand-Alone Mode ..............................................................12
Serial Data- Stand-Alone Mode .......................................................................13
Serial Clock - Stand-Alone Mode ....................................................................13
Left/Right Clock - Stand-Alone Mode ..............................................................13
Master Mode - Stand-Alone Mode ..........................................................................13
Slave Mode - Stand-Alone Mode ............................................................................13
High Pass Filter - Stand-Alone Mode .....................................................................13
Power-up and Calibration - Stand-Alone Mode ......................................................13
Synchronization of Multiple Devices - Stand Alone Mode ......................................14
CONTROL PORT MODE ..................................................................................................14
Access to Control Port Mode ..................................................................................14
Internal Power-O n Rese t ...................... ...... ..... ...... ................. ..... ...... ..... .........14
Master Clock - Control Port Mode ..........................................................................15
64× vs. 128× Oversampling Modes ................... ..... ...... ..... ...... ...... ................ ...... ...15
Serial Data Interface - Control Port Mode ..............................................................15
Serial Data - Control Port Mode ......................................................................15
Serial Clock - Control Port Mode .....................................................................15
Left/Right Clock -Control Port Mode ................................................................15
Master Mode- Control Port Mode ...........................................................................17
Slave Mode - Control Port Mode ............................................................................17
Synchronization of Multiple Devices - Control Port Mode ......................................17
Power-up and Calibration - Control Port Mode .......................................................17
High Pass Filter -Control Port Mode .......................................................................17
Input Level Monitoring - Control Port Mode ............................................................18
High Resolution Mode .....................................................................................18
Bar Graph Mode ..............................................................................................18
Dual Digital Audio Outputs .....................................................................................18
Psychoacoustic Filter ..............................................................................................19
Low Group Delay Filter ...........................................................................................19
µC Interface Formats ..............................................................................................19
SPI Mode .................. ................. ..... ...... ...... ................ ...... ...... ..... ................. ...19
I2C Mode .........................................................................................................19
Establishing the Chip Address in I2C Mode ....................................................19
ANALOG CONNECTIONS - ALL MODES .......................................................................19
GROUNDING AND POWER SUPPLY DECOUPLING - ALL MODES ............................20
DIGITAL FILTER PLOTS .................................................................................................21
REGISTER DESCRIPTION ......................... ..... ...... ...... ................ ...... ...... ..... ................. ...25
PIN DESCRIPTIONS ............ ...... ..... ...... ...... ................. ..... ...... ..... ................. ...... ..... ...... ...31
Power Supply Connections .....................................................................................31
Analog Inputs...........................................................................................................31
Analog Outputs........................................................................................................32
Digital Inputs............................................................................................................32
CS5396 CS5397
DS229PP2 3
Digital Input Pin Definitions for Stand-Alone MODE ...............................................32
Digital Pin Definitions for CONTROL-PORT MODE................................................33
Digital Outputs.........................................................................................................33
Digital Inputs or Outputs..........................................................................................34
Miscellaneous .........................................................................................................34
PARAMETER DEFINITIONS.............................................................................................35
ADDITIONAL INFORMATION.... ..... ...... ...... ................. ..... ...... ..... ................. ...... ..... ...... ...36
PACKAGE DIMENSIONS .................................................................................................37
CS5396 CS5397
4DS229PP2
ANALOG CHARACTERISTICS (TA = 25°C; VA, VL,VD = 5V; Full-scale Input Sinewave, 997 Hz;
Analog connections as shown in Figure 1; Measurement Bandwidth is 20 Hz to 20 kHz unless otherwise specified;
Logic 0 = 0V, Logic 1 = VD;
Notes: 1. Referenced to typical full-scale differential input voltage (4.0 Vpp).
2. Specified for a fully differential input ±{(AINR+)-(AINR-)}.The ADC accepts input voltages up to the
analog supplies (VA and AGND). Full-scale outputs will be produced for differential inputs beyond
VIN. * Refer to Parameter Definitions at the end of this data sheet.
Specifications are subject to change without notice.
Parameter Symbol Min Typ Max Units
Dynamic Performance
Dynamic Range MCLK equal to 24.576 MHz
Fs = 48 kHz in 128x Oversampling Mode (A-weighted)
Fs = 48 kHz in 128x mode
Fs = 96 kHz in 64x mode (A-weighted)
Fs = 96 kHz in 64x mode (40 kHz Bandwidth)
MCLK equal to 12.288 MHz
Fs = 48 kHz in 64x mode (A-weighted)
Fs = 48 kHz in 64x mode
TBD
TBD
TBD
TBD
TBD
TBD
120
117
120
114
117
114
-
-
-
-
-
-
dB
dB
dB
dB
dB
dB
Total Harmonic Distortion + Noise
Fs = 48 kHz in 128x mode -1 dB (Note 1)
-20 dB (Note 1)
-60 dB (Note 1)
Fs = 96 kHz in 64x mode -1 dB (Note 1)
(40 kHz bandwidth) -20 dB (Note 1)
-60 dB (Note 1)
Fs = 48 kHz in 64x mode -1 dB (Note 1)
-20 dB (Note 1)
-60 dB (Note 1)
THD+N TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
105
97
57
105
97
57
105
97
57
-
-
-
-
-
-
-
-
-
dB
dB
dB
dB
dB
dB
dB
dB
dB
Total Harmonic Distortion -1 dB (Note 1) THD TBD 0.00056 - %
Interchannel Phase Deviation - 0.0001 - deg
Interchannel Isolation - 120 - dB
Dynamic Range Performance Drift (following calibration) - 0.05 - dB/°C
dc Accuracy
Interchannel Gain Mismatch - 0.05 - dB
Gain Error - ±5TBD%
Gain Drift - ±100 - ppm/°C
Offset Error (With high pass filter enabled) - 0 - LSB
Analog Input
Full-scale Differential Input Voltage (Note 2) VIN TBD 4 TBD Vpp
Input Impedance Differential
Common-mode ZIN -
-4.5
TBD -
-k
k
Common-Mode Rejection Ratio CMRR - 82 - dB
CS5396 CS5397
DS229PP2 5
DIGITAL FILTER CHARACT ERISTICS (TA = 25 °C; VA, VL,VD = 5V±5%; F s = 48 kHz)
Notes: 3. Response shown is for Fs equal to 48 kHz. Filter characteristics scale with Fs.
Parameter
CS5396 CS5397
Symbol Min Typ Max Min Typ Max Unit
High-Performance Filter
Pass ban d(-0.01 dB) 0 - 0.4604 0 - 0.3958 Fs
Passband Ripple - - ±0.005 - - ±0.005 dB
Stopband 0.5542 - 63.45 0.4979 - 63.50 Fs
Stopband Attenuation 117 - - 117 - - dB
Grou p Delay (Fs = Out put Sam pl e Rate)
128x Oversampling Mode
64x Oversampling Mode
tgd -
-34/Fs
34/Fs -
--
-34/Fs
34/Fs -
-µs
µs
Group Delay Variation vs. Frequency tgd --0.0--0.0
µ
s
Low Group Delay Filter
Pass ban d(-0.01 dB) 128x Oversampling Mode
64x Oversampling Mode
0
0-
-0.375
0.188 0
0-
-0.375
0.188 Fs
Fs
Passband Ripple - - 0.015 - - 0.015 dB
Stopband 128x Oversampling Mode
64x Oversampling Mode
0.646
0.323 -
-127.35
63.68 0.646
0.323 -
-127.35
63.68 Fs
Fs
Stopband Attenuation 86 - 86 - dB
Grou p Delay (Fs = Out put Sam pl e Rate) tgd - 10/Fs - - 10/Fs - µs
Group Delay Variation vs. Frequency tgd --0.0--0.0
µ
s
High Pass Filter Characteristics
Frequency Response-3.0 dB (Note 3)
-0.036 dB (Note 3) -1.8
20 -
--1.8
20 -
-Hz
Hz
Phase Deviation@ 20Hz (Note 3) - 5.3 - - 5.3 - Deg
Passband Ripple - - 0 - - 0 dB
CS5396 CS5397
6DS229PP2
POWER AND THERMAL CHARACTERISTIC S
(TA = 25 °C; VA, VL,VD = 5V±5%; Fs = 48 kHz; Master Mode)
DIGITAL CHARACTERISTICS (TA = 25 °C; VA, VL,VD = 5V±5%)
ABSOLUTE MAXIMUM RATINGS (AGND, DGND = 0V, All voltages with respect to ground.)
Notes: 4. Any pin except supplies. Transient currents of up to ±100 mA on the analog input pins will not cause SCR
latch-up.
5. The maximum over/under voltage is limited by the input current.
6. Applies to normal operation. Greater differences during power up/down will not cause SCR latch-up.
WARNING: Operation beyond these limits may result in permanent damage to the device.
Normal operation is not guaranteed at these extremes.
Parameter
64X oversampling
MCLK=12.288 MHz 128X oversampling
MCLK=24.576 MHz
Symbol Min Typ Max Min Typ Max Unit
Power Supply Current VA+VL
(Normal Operation) VD IA
ID
-
-150
65 TBD
TBD -
-160
125 TBD
TBD mA
mA
Power Supply Current VA+VL
(Power-Down Mode) VD IA
ID
-
-2
2-
--
-3
3.5 -
-mA
mA
Power Consum pti on(Norm al Op er ati on)
(Power-Down Mode) -
-1075
20 TBD
--
-1425
33 TBD
-mW
mW
Power Supply Rejection Ratio (1 kHz) PSRR - 65 - - 65 - dB
Allowable Junction Temperature - - 135 - - 135 °C
Junction to Ambient Thermal Impedance TJA -45- -45-
°
C/W
Parameter Symbol Min Typ Max Units
High-Level Input Voltage VIH 2.4 - - V
Low-Level Input Voltage VIL --0.8V
High-Level Output Voltage at Io = -20 µAV
OH VD - 1.0 - - V
Low-Level Output Voltage at Io = 20 µAV
OL --0.4V
Input Leakage Current Iin --
±
10 µA
Parameter Symbol Min Typ Max Units
DC Power Supplies: Analog
Logic
Digital
|VA - VD|
(Note 6)
|VA - VL|
(Note 6)
|VD - VL|
(Note 6)
VA
VL
VD
-0.3
-0.3
-0.3
-
-
-
-
-
-
-
-
-
+6.0
+6.0
+6.0
0.4
0.4
0.4
V
V
V
V
V
V
Input Current (Note 4) Iin --
±
10 mA
Analog Input Voltage (Note 5) VIN AGND-0.7 - VA+0.7 V
Digital Input Voltage (Note 5) VIND -0.3 - VD+0.7 V
Ambient Operating Temperature (Power Applied) TA-55 - +50 °C
Storage Temperature Tstg -65 - +150 °C
CS5396 CS5397
DS229PP2 7
RECOMMENDED OPERATING CONDITIONS (AGND, DGND = 0V, all voltages with respect
to ground.)
Specifications are subject to change without notice.
SWITCHING CHARACTERISTICS (TA = 25 °C; VA = 5V±5%; Inputs: Logic 0 = 0V,
Logic 1 = VA = VD; CL = 20 pF)
Parameter Symbol Min Typ Max Units
DC Power Supplies: Positive Digital
Positive Logic
Positiv e Ana lo g
|VA - VD|
(Note 6)
VD
VL
VA
4.75
4.75
4.75
-
5.0
5.0
5.0
-
5.25
5.25
5.25
0.4
V
V
V
V
Ambient Operating Temperature (Power Applied) TA-10 - +50 °C
Parameter Symbol Min Typ Max Units
Output Sample Rate Fs 2 - 100 kHz
MCLK Period tclkw 39.06 - 1950 ns
MCLK Low tclkl 26 - - ns
MCLK High tclkh 26 - - ns
MCLK Fall Time tclkft --8ns
Master Mode
SCLK falling to LRCK tmslr -20 - +20 ns
SCLK falling to SDATA valid tsdo - - 20 ns
SCLK duty cycle - 50 - %
Slave Mode
LRCK Period 1/Fs 10 - 500 µs
LRCK duty cyc le - 50 - %
SCLK Period tsclkw 4 x tclw --ns
SCLK Pulse Width Low tsclkl 2 x tclw --ns
SCLK Pulse Width High tclkh 60 - - ns
SCLK falling to SDATA valid tdss --t
clw + 20 ns ns
LRCK edge to MSB valid tlrdss --t
clw + 20 ns ns
SCLK rising to LRCK edge delay tslr1 tclw + 20 ns - - ns
LRCK edge to rising SCLK setup time tslr2 tclw + 20 ns - - ns
CS5396 CS5397
8DS229PP2
SCLK output
t
mslr
SDATA
t
sdo
LRCK output
MSB MSB-1
SCLK to SDATA & LRCK - MASTER mode
Serial Data Format, Left Justified
SCLK output
t
mslr
SDATA
t
sdo
LRCK output
MSB
SCLK to SDATA & LRCK - MASTER mode
Serial Data Format, I2S compatible
SDATA
SCLK input
LRCK input
sclkl
t
dss
t
MSB MSB-1 MSB-2
lrdss
t
sclkh
t
slr1
t
slr2
t
tsclkw
SCLK to LRCK & SDATA - SLAVE mode
Serial Data Format, Left Justified
SDATA
SCLK input
LRCK input
sclkl
t
dss
t
MSB MSB-1
sclkh
t
slr1
t
slr2
t
t
sclkw
SCLK to LRCK & SDATA - SLAVE mode
Serial Data Format, I2S compatible
CS5396 CS5397
DS229PP2 9
SPI CONTROL PORT SWITCHING CHARACTERISTICS (TA = 25 °C; VD, VA = 5V ±5%;
Inputs: Logic 0 = DGND, Logic 1 = VD; CL = 20 pF)
Notes: 7. Data must be held for sufficient time to bridge the transition time of CCLK.
8. For FSCK < 1 MHz.
Parameter Symbol Min Max Unit
SPI Mode
CCLK Clock Frequency fsck -6MHz
CS High Time Between Transmissions tcsh 1.0 - µs
CS Falling to CCLK Edge tcss 20 - ns
CCLK Low Time tscl 66 - ns
CCLK High Time tsch 66 - ns
CDIN to CCLK Rising Setup Time tdsu 40 - ns
CCLK Rising to DATA Hold Time (Note 7) tdh 15 - ns
Rise Time of CCLK and CDIN (Not e 8) tr2 -100ns
Fall Time of CCLK and CDIN (Note 8) tf2 -100ns
t
r2
t
f2
tdsu t
dh
t
sch
tscl
CS
CCLK
CDIN
tcss tcsh
CS5396 CS5397
10 DS229PP2
I2C CONTROL PORT SWITCHING CHARACTERISTICS (TA = 25 °C; VD, VA = 5V ± 5%;
Inputs: Logic 0 = DGND, Logic 1 = VD; CL = 20 pF)
Notes: 9. Use of the I2C® bus interface requires a license from Philips.
10. Data must be held for sufficient time to bridge the 300 ns transition time of SCL.
Parameter Symbol Min Max Unit
I
2
C
®
Mode (Note 9)
CCLK Clock Frequency fscl -100kHz
Bus Free Time Between Transmissions tbuf 4.7 - µs
Start Condition Hold Time (prior to first clock pulse) thdst 4.0 - µs
Clock Low T ime tlow 4.7 - µs
Clock High Time thigh 4.0 - µs
Setup Time for Repeated Start Condition tsust 4.7 - µs
CDIN Hold Time from CCLK Falling (Note 10) thdd 0-µs
CDIN Setup Time to CCLK Rising tsud 250 - ns
Rise Time of Both CDIN and CCLK Lines tr-1µs
Fall Time of Both CDIN and CCLK Lines tf-300ns
Setup Time for Stop Condition tsusp 4.7 - µs
t
buf thdst
t
hdst
t
low
t
r
t
f
t
hdd
thigh
t
sud
t
sust
t
susp
Stop Start Start Stop
Repeated
CDIN
CCLK
CS5396 CS5397
DS229PP2 11
Audio
Data
Processor
VREF
AINL+
AINL-
TSTO1
TSTO2
VD
6.8nF
0.1
µ
F
Left Analog Input -
Left Analog Input +
A/D CONVERTER
SCLK
SDATA2
CS5396/7
CDIN/DFS
CCLK/SM
Timing
Logic
& Cl ock
MCLKA
AINR+
Right Analog Input - AINR-
Right Analog Input +
VCOM
470
µ
F+
LRCK
TSTO pins should be left
floating, with no trace
attached
39
CS/PDN
µ
-Controller/
Configuration
ADCTL
DACTL
VA VL
+5V Analog
1
µ
F
0.1
µ
F
+5V Digital
5
0.1
µ
F
0.1
µ
F
1
µ
F
+
+
100
µ
F
+
0.1
µ
F
SDATA1
AGND1LGND DGND AGND2
3
12 28
25
21
8
6
9
20
7
14
13
15
17
18
19
11
2324
1
2
4
5
27
26
39
39
39
6.8nF
MCLKD
AGND0
22
16
CAL 10
Figure 1. Typical Connection Diagram
CS5396 CS5397
12 DS229PP2
GENERAL DESCRIPTION
The CS5396/97 is a 24-bit, stereo A/D converter
designed for stereo digital audio applications. The
analog input channels are simultaneously sampled
by separate, patented, 7th- order tr i-level delta-sig-
ma modulators at either 128 or 64 times the output
sample ra te (64×Fs or 128×Fs) of the device. The
resulting serial bit streams are digitally filtered,
yielding pairs of 24-bit values at output sample
rates (Fs) of up to 100 kHz. This technique yields
nearly ideal conversion performance independent
of input frequency and amplitude. The converter
does not require difficult-to-design or expensive
anti-alias filters, and it does not require external
sample-and-hold amplifiers or voltage references.
Only normal power supply decoupling compo-
nents, voltage reference bypass capacitors and a
single resistor and capacitor on each input for anti-
aliasing are required, as shown in Figure 1. An on-
chip voltage reference provides for a differential
input signal range of 4.0 Vpp. The device also con-
tains a high pass filter, implemented digitally after
the decimation filter, to completely eliminate any
internal offsets in the converter or any offsets
present at the input circuitry to the device. Output
data is available in serial form, coded as 2’s com-
plement 24-bit numbers. For more information on
delta-sigma modulation techniques see the refer-
ences at the end of this data sheet.
Stand-Alone vs. Control Port Mode
The CS5396/97 can operate in either Stand-Alone
or Control Port Mode. The functionality of pi ns 17,
18 and 19 is established upon entering either the
Stand-Alone or Control Port mode, as described in
the Pin Description section.
The Control Port Mode requires a micro-controller
and allows access to many additional features,
which include:
128× Oversampling Mode
Reduction of 24-bit data to 20, 18 or 16-bit data
with psychoacoustically optimized dither
Programmability of psychoacoustic filter coef-
ficients
Peak Input Signal Level Monitor with either
High Resolution or Bar Graph mode selection
Signal inversion
High pass filter defeat
Mute
Access to the digital filter to allow the input of
external digital audio data to produce a two-to-
one decimated output and/or psychoacoustic bit
reduction.
STAND-ALONE MODE
Master Clock - Stand-Alone Mode
The master clock is the clock source for the delta-
sigma modulator sampling (MCLKA) and digital
filters (MCLKD). The required MCLKA/D fre-
quency is d etermined by the d esired Fs and must be
256×Fs. Table 1 shows some common master
clock frequencies.
Table 1. Common Clock Frequencies for Stand-Alone
Mode
Serial Data Interface - Stand-Alone Mode
The CS5396/97 supports two serial data formats
which are selected via the digital format select pin,
DFS. The digital output format determines the rela-
tionship between the serial data, left/right clock and
serial clock. Figures 2 and 3 detail the interface for-
LRCK
(kHz) MCLKA/D
(MHz) SCLK
(MHz)
32 8.192 2.048
44.1 11.2896 2.822
48 12.288 3.072
64 16.384 4.096
88.2 22.5792 5.6448
96 24.576 6.144
CS5396 CS5397
DS229PP2 13
mats. The serial data interface is accomplished via
the serial data outputs; SDATA1 and SDATA2; se-
rial data clock, SCLK, and the left/right clock,
LRCK. The serial nature of the output data results
in the left and right data words being read at differ-
ent times. However, the samples within an LRCK
cycle represent simultaneously sampled analog in-
puts.
Serial Data- Stand-Alone Mode
The serial data block consists of 24 bits of audio
data presented in 2’s-complement format with the
MSB-first. The data is clocked from SDATA1 and
SDATA2 by the serial clock and the channel is de-
termined by the Left/Right clock. The full precision
24-bit data is available on SDATA1 and the output
from the low group delay filter is available on
SDATA2.
Serial Clock - Stand-Alone Mode
The serial clock shifts the digitized audio data from
the internal data registers via the SDATA1 and
SDATA2 pins. SCLK is an output in Master Mode
where internal dividers will divide the master clock
by 4 to generate a serial clock which is 64×Fs. In
Slave Mode, SCLK is an input with a serial clock
typically between 48× and 128×Fs. However, it is
recommended that SCLK be e qual to 64×, though
other frequencies are possible, to avoid potential
interference effects which may degrade system per-
formance.
Left/Right Clock - Stand-Alone Mode
The Left/Right clock, LRCK, determines which
channel, left or right, is to be output on SDATA1
and SDATA2. In Master Mode, LRCK is an output
whose frequency is equal to Fs. In Slave Mode,
LRCK is an input whose fr equency must be equal
to Fs and synchronous to MCLKA/D.
Master Mode - Stand-Alone Mode
In Master mode, SCLK and LRCK are outputs
which are internally derived from the master clock.
Internal dividers will divide MCLKA/D by 4 to
generate a SCLK which is 64×Fs and by 256 to
generate a LRCK which is equal to Fs. The
CS5396/97 is placed in the Master mode with the
slave/master pin, S/M, low.
Slave Mode - Stand-Alone Mode
LRCK and SCLK become inputs in SLAVE mode.
LRCK must be externally derived from MCLKA/D
and be equal to Fs. It is recommended that SCLK
be equal to 64×. Other frequencies between 48×
and 128×Fs are possible but may degrade system
performance due to interference effects. The mas-
ter clock frequency must be 256×Fs. The
CS5396/97 is placed in the Slave mode with the
slave/master pin, S/M, high.
High Pass Filter - Stand-Alone Mode
The CS5396/97 includes a high pass filter after the
decimator to remove the DC offsets introduced by
the analog buffe r stage and the CS5396/97 analog
modulator. The characteristics of this first-order
high pass filter are outlined below, for Fs equal to
48 kHz. This filter response scales linearly with
sample rate.
Frequency response: -3 dB @ 1.8 Hz
-0.036 dB @ 20 Hz
Phase deviation: 5.3 degrees @ 20 Hz
Passband ripple: None
Power-up and Calibration - Stand-Alone
Mode
The delta-sigma modulators settle in a matter of
microseconds after the analog section is powered,
either through the application of power or by exit-
ing the power-down mode. However, the voltage
reference will take a much longer time to reach a fi-
nal value due to the presence of external capaci-
tance on the VREF pin. A time delay of
approximately 10ms/µF is required after applying
power to the device or after exiting a power down
state.
CS5396 CS5397
14 DS229PP2
A calibration of the tri-level delta-sigma modulator
should always be initiated following power-up and
after allowing suffici ent time for the voltage on the
external VREF capacitor to settle. This is required
to minimize noise and distortion. It is also advised
that the CS5396/97 be calibrated after the device
has reached th ermal equilibrium, approximate ly 10
seconds, to maximize performance.
Synchronization of Multiple Devices -
Stand Alone Mode
In systems where multiple ADCs are required, care
must be taken to achieve simultaneous sampling. It
is recommended that the rising edge of the CAL
signal be timed with a falling edge of MCLK to en-
sure that all devices will initiate a calibration and
synchronization sequence on the same rising edge
of MCLK. The absence of re-timing of the CAL
signal can result in a sampling difference of one
MCLK period.
CONTROL PORT MODE
Access to Control Port Mode
The mode selection between Stand-Alone and Con-
trol Port Mode is determined by the state of the
SDATA1 pin 250 MCLK cycles following the in-
ternal power-on reset. A 47 k pull-up resistor on
SDATA1 will select the Control Port Mode. How-
ever, the control port will not respond to CCLK and
CDIN until the pull-up on the SDATA1 pin is re-
leased.
Internal Power-On Reset
The timing required to determine Control port
mode and I2S/SPI mode is based on an internal
power-on reset. The internal power-on reset re-
quires the power supply to exceed a threshold volt-
age. However, there is no external indication of
when the internal reset is activated. If precise tim-
ing of the Control port and I2S/SPI decisions is re-
quired, MCLK should not be applied until the
power supply has stabilized.
SDATA 23 22 7 6 23 22
SCLK
LRCK
23 22
MASTER
24-Bit Left Justified Data
Data Valid on Rising Edge of 64x SCLK
MCLK equal to 256x Fs
5432108
SLAVE
24-Bit Left Justified Data
Data Valid on Rising Edge of SCLK
MCLK equal to 256x Fs
97654321089
Left
Right
Figure 2. Serial Data Format 0, Stand-Alone Mode, DFS low. Left Justified.
SDATA 23 22 8 7 23 22
SCLK
LRCK
23 22
MASTER
I S 24-Bit Data
Data Valid on Rising Edge of 64x SCLK
MCLK equal to 256x Fs
2
SLAVE
I S 24-Bit Data
Data Valid on Rising Edge of SCLK
MCLK equal to 256x Fs
2
6543210 8765432109 9
Left Right
Figure 3. Serial Data Format 1, Stand-Alone Mode, DFS High. I2S compatible
CS5396 CS5397
DS229PP2 15
Master Clock - Control Port Mode
The master clock is the clock source for the delta-
sigma modulator sampling (MCLKA) and digital
filters (MCLKD). The required MCLKA/D fre-
quency is determined by the desired Fs and the cho-
sen Oversampling Mode. Table 2 shows some
common master clock frequencies.
64× vs. 128× Oversampling Modes
The CS5396/97 can operate in a 64× Oversampling
Mode with a 256× master clock (MCLKA/D) at a
maximum sample rate of 100 kHz. The device ca n
also operate in a 128× Over sampling Mode with a
512× master clock (MCLKA/D) where the maxi-
mum Fs is 50 kHz. Notice that the required master
clock is 24.576 MHz for Fs equal to either 48 kHz
in the 128× Oversampling Mode or 96 kHz in the
64× Oversampling Mode. The sampling mode is
set via the control re gister which alte rs the de cima-
tion ratio of the digital filter. The 64× Oversam-
pling Mode is the default mode. Table 2 shows
some common clock frequencies for both modes.
Refer to Appendix A for additional discussion of
64× vs. 128× Oversampling Modes.
Table 2. Common Clock Frequencies
Serial Data Interface - Control Port Mode
The CS5396/97 supports two serial data formats
which are selected via the control register. The dig-
ital output format determines the relationship be-
tween the serial data, left/right clock and serial
clock. Figures 4 - 7 detail the interface formats.
The serial data interface is accomplished via the se-
rial data outputs; SDATA1 and SDATA2, serial
data clock, SCLK, and the left/right clock, LRCK.
The serial nature of the output data results in the left
and right data words being read at different times.
However, the samples within an LRCK cycle repre-
sent simultaneously sampled analog inputs.
Serial Data - Control Port Mode
The serial data block is presented in 2’s-comple-
ment format with the MSB-first. The data is clocked
from SDATA1 and SDATA2 by the serial clock
and the channel is determined by the Left/Right
clock. The full precision 24 bit data is available on
SDATA1 and the output from the low group delay
is available on SDATA2.
The serial data can be followed by 8 Peak Signal
Level, PSL, bits as shown in Figures 4 - 7 if the
PKEN bit is set. Refer to the Dual Audio Output
section of this data sheet for further discussion of
SDATA1 and SDATA2 options.
Serial Clock - Control Port Mode
The serial clock shifts the digitized audio data from
the internal data registers via SDATA1 and
SDATA2. SCLK is an output in Master Mode
where internal dividers will divide the master clock
by 4 to generate a serial clock which is 64×Fs in
the 64× Oversampling Mode. In the 128× Over-
sampling Mode, internal dividers will divide
MCLKA/D by 4 to generate a SCLK which is 128×
Fs. In Slave Mode, SCLK is an input with a serial
clock typically between 48× and 128×Fs. It is rec-
ommended that SCLK be equal to 64× in the 64×
Oversampling Mode and equal to 128× in the 128×
Oversampling Mode to avoid possible system per-
formance degradation due to interference effects.
Left/Right Clock -Control Port Mode
The Left/Right clock, LRCK, determines which
channel, left or right, is to be output on SDATA1
LRCK
(kHz) Over-
sampling MCLKA/D
(MHz) SCLK
(MHz)
32 64 8.192 2.048
44.1 64 11.2896 2.822
48 64 12.288 3.072
32 128 16.384 4.096
44.1 128 22.5792 5.6448
48 128 24.576 6.144
64 64 16.384 4.096
88.2 64 22.5792 5.6448
96 64 24.576 6.144
CS5396 CS5397
16 DS229PP2
SDATA P1 P024 23 9 P7 P6 P5 P4 P3 P28 24 23
SCLK
LRCK
P1 P024 23 9 P7 P6 P5 P4 P3 P28
MASTER
24-Bit Left Justified Data
Data Valid on Rising Edge of 64x SCLK
MCLK equal to 256x Fs
SLAVE
24-B i t Left Justif ied Data
Data Valid on Rising Edge of SCLK
MCLK equal to 256x Fs
10325476 76543210
Left Right
Figure 4. Control Port Mode, Serial Data. Left Justified. 64x Oversampling Mode
The peak signal level bits are available only if Bit 6 of Byte 7 is set.
SCLK
LRCK
MASTER
I S 24-Bit Data
Data Valid on Rising Edge of 64x SCLK
MCLK equal to 256x Fs
2
SLAVE
I S 24-Bit Data
Dat a Val id on R i sing E dge of SCL K
MCLK equal to 256x Fs
2
SDATA P1 P024 23 9 P7 P6 P5 P4 P3 P28 24 23P1 P024 23 9 P7 P6 P5 P4 P3 P2810325476 76543210
Left Right
Figure 5. Control Port Mode, Serial Data. I2S Compatible. 64x Oversampling Mode.
The peak signal level bits are available only if Bit 6 of Byte 7 is set.
SDATA P1 P023 22 P7 P6 P5 P4 P3 P2
SCLK
LRCK
23 22
MASTER
24-Bit Left Justified Data
Data Valid on Rising Edge of 128x SCLK
MCLK equal to 512x Fs
SLAVE
24-Bit Left Justified Data
Data Valid on Rising Edge of SCLK
MCLK equal to 512x Fs
10 P1 P0P7 P6 P5 P4 P3 P2 23 2210
Left Right
Figure 6. Control Port Mode, Serial Data. Left J ustified. 128x Oversampling Mode
The peak signal level bits are available only if Bit 6 of Byte 7 is set.
SDATA P1 P023 22 P7 P6 P5 P4 P3 P2
SCLK
23 2210 P1 P0P7 P6 P5 P4 P3 P2 23 2210
LRCK
MASTER
I S 24-Bit Data
Data Valid on Rising Edge of 128x SCLK
MCLK equal to 512x Fs
2
SLAVE
I S 24-Bit Data
Data Valid on Rising Edge of SCLK
MCLK equal to 512x Fs
2
Left Right
Figure 7. Control Port Mode, Serial Data. I2S Compatible. 128x Oversampling Mode.
The peak signal level bits are available only if Bit 6 of Byte 7 is set.
CS5396 CS5397
DS229PP2 17
and SDATA2. In Master Mode, LRCK is an output
whose frequency is equal to Fs. In Slave Mode,
LRCK is an input whose fr equency must be equal
to Fs and synchronous to MCLKA/D.
Master Mode- Control Port Mode
In Master mode, SCLK and LRCK are outputs
which are internally derived from the master clock.
In the 64× Oversampling Mode, internal dividers
will divide MCLKA/D by 4 to generate a SCLK
which is 64×Fs and by 256 to generate a LRCK
which is equal to Fs. In the 128× Oversampling
Mode, internal dividers will divide MCLKA/D by
4 to generate a SCLK which is 128×F s and by 512
to generate a LRCK which is equal to Fs. The
CS5396/97 is placed in the Master mode via the
control register.
Slave Mode - Control Port Mode
LRCK and SCLK become inputs in SLAVE mode.
LRCK must be externally derived from MCLKA/D
and be equal to Fs. It is recommended that SCLK
be equal to 64× in the 64× Oversampling Mode and
equal to 128× in the 128× Oversampling Mode.
Other frequencies are possible but may degrade
system performance due to interference effects.
The CS5396/97 is placed in the Slave mode via the
control register.
Synchronization of Multiple Devices -
Control Port Mode
In systems where multiple ADCs are required, care
must be taken to achieve simultaneous sampling.
The FSTART bit in register 1 controls the synchro-
nization of the internal clocks and sampling pro-
cess between the a nalog modulator and the digital
filter. Multiple ADCs can be synchronized if the
FSTART command is ini tiated on the same edge of
MCLK. This can be accomplished by re-timing the
CCLK clock with the falling edge of MCLK. This
is a relatively simple matter if the ADCs have the
same address. However, if the system requires the
devices to have individual a ddresses, synchroniza-
tion can be accomplished by;
1) Disable the address enable bit (ADDREN) in
register 7
2) Issue a system broadcast FSTART command
synchronized with CCLK.
3) Reset the ADDREN bit.
Power-up and Calibration - Control Port
Mode
The delta-sigma modulators settle in a matter of
microseconds after the analog section is powered,
either through the application of power or by exit-
ing the power-down mode. However, the voltage
reference will take a much longer time to reach a fi-
nal value due to the presence of external capaci-
tance on the VREF pin. A time delay of
approximately 10ms/µF is required after applying
power to the device or after exiting a power down
state.
A calibration of the tri-level delta-sigma modulator
should always be initiated following power-up and
after allowing sufficient t ime for the volta ge on the
external VREF capacitor to settle. This is required
to minimize noise and distortion. It is also advised
that the CS5396/97 be calibrated after the device
has reached thermal equilibrium to maximize per-
formance. A calibration sequence requires the fol-
lowing commands;
1) set the FSTART bit
2) set the GND CAL bit
3) set the CAL bit
4) Wait a minimum of 2050 LRCK periods in the
128x mode or 4100 LRCK periods in the 64x
mode.
5) Remove GND CAL
High Pass Filter -Control Port Mode
The CS5396/97 includes a high pass filter after the
decimator to remove the DC offsets introduced by
CS5396 CS5397
18 DS229PP2
the analog buffer stage and the CS5396/97 analog
modulator. The high pass filter can be defeated
with the control register. It is also possible to write
to the left/right offset registers to establ ish a prede-
termined offset.
The characteristics of this first-order high pass fil-
ter are outlined below for Fs equal to 48 kHz. The
filter response scales linearly with sample rate.
Frequency response: -3 dB @ 1.8 Hz
-0.036 dB @ 20 Hz
Phase deviation: 5.3 degrees @ 20 Hz
Passband ripple: None
Input Level Monitoring - Control Port Mode
The CS5396/97 includes independent Peak Input
Level Monitoring for each channel. The analog-to-
digital converter continually monitors the peak dig-
ital signal for both channels and records these val-
ues in the Active registers. This information can be
transferred to the Output registers by writing the
PU (Peak Update) bit which will also reset the Ac-
tive register. The Active register contains the peak
signal level since the previous peak update request.
The 8-bit contents of the output registers are avail-
able in both interface modes. The peak signal level
information is available in two format s - High Res-
olution Mode and Bar Graph Mode. The output for-
mat is controlled via the control register.
High Resolution Mode
Bits P7-P0 indicate the Peak Signal Level (PSL)
since the previous peak update (or previous write of
the PU bit). If the ADC input lev el is less than full-
scale, bits P5-P0 represent the peak value from -
60 dB to 0 dB of full scale in 1 dB steps. The PSL
outputs are accurate to within 0.25 dB. Bit P6 pro-
vides a coarse means of determining an ADC input
idle condition. Bit P7 indicates an ADC overflow
condition if the ADC input level is greater than
full-scale.
P7 - Overrange
0 - Analog input less than full-scale level
1 - Analog input greater than full-scale
P6 - Idle channel
0 - Analog input >-60 dB from full-scale
1 - Analog input <-60 dB from full-scale
P5 to P0 - Input Level Bits (1 dB steps)
Inputs <0 dB P5 - P0
0 dB 000000
-1 dB 000001
-2 dB 000010
-60 dB 111100
Bar Graph Mode
This mode provides a decoded output format which
indicates the peak input signal level in a “Bar
Graph” format which can be used to drive front
panel LEDs. This decoded output can be used to
drive front panel LEDs.
Input Level T7 - T0
Overflow 11111111
0 dB to -3 dB 01111111
-3 dB to -6 dB 00111111
-6 dB to -10 dB 00011111
-10 dB to -20 dB 00001111
-20 dB to -30 dB 00000111
-30 dB to -40 dB 00000011
-40 dB to -60 dB 00000001
< - 60 dB 00000000
Dual Digital Audio Outputs
The CS5396/97 contains two stereo digital audio
output channels - SDATA1 and SDATA2. These
audio o utput channels are completely i ndependent,
as SDATA1 can contain 24-bit audio data simulta-
neou s with p sychoaco ustic au dio dat a on SDAT A2.
Another example of this independence is 24-bit au-
dio dat a out put on SDATA1 simu ltan eously with a
low group delay output on SDATA2.
The audio output formats are completely program-
mable through the I2C/SPI µC interface. The output
CS5396 CS5397
DS229PP2 19
formats include: inverted output, psychoacoustic
output (16-bit, 18-bit, 20-bit), and low group delay
output.
Psychoacoustic Filter
The CS5396/97 includes a programmable 10 tap
digital filter which can be used to perform psycho-
acoustic noise-shaping of the audio spectrum if
desired. The filter ca n implement a variety of 16-
bit, 18-bit, or 20-bit noise-shaped responses by
setting the digital filter coefficients. Further dis-
cussion of the psychoacoustic filter can be found
in Appendix C.
Appendix B discusses an application using the psy-
choacoustic filter independently of the A/D con-
verter function. In this mode, SDATA2 becomes an
input to the psychoacoustic filter stage and
SDATA1 is the digital audio output.
Low Group Delay Filter
The characteristics of the low group delay filter are
shown in Figures 17 - 24.
µC Interface Formats
The device supports either SPI or I2C interface for-
mats. The CS5396/97 monitors the state of CS dur-
ing power-up and will configure to an SPI interface
if the pin is held low. Conversely, if the pin is held
high, the port will configure to a I2C interface.
SPI Mode
In SPI mode, CS is the chip select signal, CCLK is
the µC bit clock and CDIN is the input data line
from the microcontroller. Notice that it is not pos-
sible to read the CS5396/97 registers in SPI mode
due to the lack of a data output pin.
To write to a register, bring CS low. The first 7 bits
on CDIN are the chip address, and must be zero.
The eighth bit is a read/write indicator (R/W)
which must be low.
The next 8 bits form the Memory Address Pointer
(MAP), which is set to the address of the register
that is to be updated. The next 8 bits are the data
which will be placed into t he register designated by
the MAP.
The CS5396/97 has a MAP auto increment, which
will increment the MAP after each byte is written,
allowing block writes of successive registers.
I2C Mode
In I2C mode, CDIN is a bidirectional data line.
Data is clocked into and out of the part by CCLK.
The eighth bit of the address byte is the R/W bit
(high for a read, low for a write). If the operation is
a write, the next byte is the Memory Address Point-
er which sele cts the register to be rea d or written. If
the operation is a read, the contents of the register
pointed to by the Memory Address Pointer will be
output. MAP allows successive reads or writes of
consecutive registers. Each byte is sepa rated by an
acknowledge bit. Use of the I2C bus compatible in-
terface requires a license from Phi lips. I2C bus in a
registered trademark of Philips Semiconductors.
Establishing the Chip Address in I2C Mode
Connecting SDATA1 pin and CS to 5 volts during
power-up will set the device to the Control Port and
I2C mode. However, the control port will not re-
spond to CCLK and CDATA until the hold on the
SDATA1 pin is released. The chip address can be
set by:
1) Release the hold on the SDATA1 pin of the de-
vice to be addressed.
2) Program the chip address and set the Address
Enable bit, addren, which will prevent further
communication to this device without the cor-
rect address.
3) Repeat steps 1 and 2 for the remaining devices
on the bus.
ANALOG CONNECTIONS - ALL MODES
Figure 1 shows the analog input connections. The
analog inputs are presented differentially to the
CS5396 CS5397
20 DS229PP2
modulators via the AINR+/- and AINL+/- pins.
Each analog input will accept a maximum of
2.0 Vpp. The + and - input signals are 180° out of
phase resulting in a differential input voltage of
4.0 Vpp. Figure 8 shows the input signal levels for
full scale.
The analog modulator samples the input at
6.144 MHz (MCLK=24.576 MHz) corresponding
to Fs equal to 48 kHz in the 128× Oversampling
Mode and Fs equal to 96 kHz in the 64× Oversam-
pling Mode. The digital filter will reject signals
within the stopband of the filter. However, there is
no rejection for input signals which are
(n ×6.144 MHz) ± the digital passband frequency,
where n=0,1,2,...A 39 resistor in ser ies with the
analog input and a 6.8 nF COG capacitor between
the inputs will attenuate any noise energy at
6.144 MHz, in addition to providing the optimum
source impedance for the modulators. The use of
capacitors which have a large voltage coefficient
(such as general purpose ceramics) must be avoid-
ed since these can degrade signal linearity. If active
circuitry prece des the ADC, it is recommended that
the above RC filter is placed between the active cir-
cuitry and the AINR and AINL pins. The above ex-
ample frequencies scale linearly with output
sample rate.
The on-chip voltage reference and the common
mode voltage are available at VREF and VCOM
for the purpose of decoupling only. However, due
to the sensitivity of this node, the circuit traces at-
tached to these pins must be minimal in length and
no load current may be taken from VREF. It is pos-
sible to use VCOM as a reference voltage to bias
the input buffer circuits, if the circuit trace is very
short and VCOM is buffered at the converter (refer
to the CDB53965/97). The recommended decou-
pling scheme for VREF, Figure 1, is a 470 µF elec-
trolytic capacitor and a 0.1 µF ceramic capacitor
connected from VREF to AGND. The recommend-
ed decoupling scheme for VCOM, Figure 1, is a
100 µF electrolytic capac itor and a 0.1 µF ceramic
capacitor connected from VCOM to AGND.
GROUNDING AND POWER SUPPLY
DECOUPLING - ALL MODES
As with any high resolution converter, the ADC re-
quires careful attention to power supply and
grounding arrangements if its potential perfor-
mance is to be realized. Figure 1 shows the recom-
mended power arrangements, with VA and VL
connected to a clean +5 V supply. VD, which pow-
ers the digital filter, should be run from the system
+5 V logic supply, provided that it is not excessive-
ly noisy (< ±50 mV pk-to-pk). Decoupling capaci-
tors should be as near to the ADC as possi ble, with
the low value ceramic capacitor being the nearest.
The printed circuit board layout should have sepa -
rate analog and digital regions and ground planes,
with the ADC straddling the boundary. All signals,
especially clocks, should be kept away from the
VREF pin in order to avoid unwanted coupling into
the modulators. The VREF decoupling capacitors,
particularly the 0.01 µF, must be positioned to min-
imize the electrical path from VREF and pin 3,
AGND. The CDB5396/97 evaluation board dem-
onstrates the optimum layout and power supply ar-
rangements, as well as allowing fast evaluation of
the ADC.
To minimize digital noise, connect the ADC digital
outputs only to CMOS inputs.
+3.5 V
+2.5 V
+1.5 V
+3.5 V
+2.5 V
+1.5 V
CS5396/97
AIN+
AIN-
Full Scale Input level= (AIN+) - (AIN-)= 4.0 Vpp
Figure 8. Full scale input voltage
CS5396 CS5397
DS229PP2 21
DIGITAL FILTER PLOTS
Figures 9-24 show the performance of the digital
filters included in the ADC. All plots are normal-
ized to Fs. Assuming a sample rate of 48 kHz, the
0.5 frequency point on the plot refers to 24 kHz.
The filter frequency response scales precisely with
Fs.
Magnitude (dB)
Normalized Frequency (Fs)
Magnitude (dB)
Norm a li zed Fre qu enc y (Fs )
Figure 9. CS5396 Stop Band Attenuation Figure 10. CS5396 Passband Ripple
Magnitude (dB)
Normalized Frequency (Fs)
Magnitude (dB)
Normalized Frequency (Fs)
Figure 11. CS5396 Transition Band Figure 12. CS5396 Transition Band
CS5396 CS5397
22 DS229PP2
Magnitude (dB)
Normalized Frequency (Fs)
Magnitude (dB)
Norm a li zed Fre qu enc y (Fs )
Figure 13. CS5397 Stop Band Attenuation Figure 14. CS5397 Passband Ripple
Magnitude (dB)
Normalized Frequency (Fs)
Magn i tude (dB)
Normalized Frequency (Fs)
Figure 15. CS5397 Transition Band Figure 16. CS5397 Transition Band
CS5396 CS5397
DS229PP2 23
Magnitude (dB)
Normalized Frequency (Fs)
Magnitude (dB)
Norm a li zed Fre qu enc y (Fs )
Figure 17. Low Group Delay Filter
Stop Ba nd Attenuation
64x Ov ersampling Mo de
Figure 18. Low Group Delay Filter
Passband Ripple
64x Oversam plin g Mode
Magnitude (dB)
Normalized Frequency (Fs)
Magnitude (dB)
Normalized Frequency (Fs)
Figure 19. Low Group Delay Filter
Transition Band
64x Ov ersampling Mo de
Figure 20. Low Group Delay Filter
Transition Band
64x Oversam plin g Mod e
CS5396 CS5397
24 DS229PP2
Figure 21. Low Group Delay Filter
Stop Ba nd Attenuation
128x Oversampling Mode
Figure 22. Low Group Delay Filter
Passband Ripple
128x Oversampling Mode
Figure 23. Low Group Delay Filter
Transition Band
128x Oversampling Mode
Figure 24. Low Group Delay Filter
Transition Band
128x Oversampling Mode
CS5396 CS5397
DS229PP2 25
REGISTER DESCRIPTION
** “default” ==> bit status after power-up-sequence
Analog control (address 00000001)
FSTART (Frame start)Default = ‘0’.
This bit must be set to ‘1’ to synchronize the modulator output and the decimation filter input
and is automatically reset to ‘0’ after a “fstart” pulse is sent to the analog and digital block.
GNDCAL (Ground calibration enable)
Default = ‘0’.
Modulator input is tied to internal “Vcom” when this bit is ‘1’.
AAPD (Analog Section of modulator in power down)
Default = ‘0’.
The analog section of the modulator is in power down mode when aapd = ‘1’.
ADPD (Digit al Sec ti on of modul ato r in power down )
Default = ‘0’.
The digital section on the modulator is in power down mode when adpd = ‘1’.
TEST BIT Default =’0’.
Must remain at 0.
Mode (address 00000010)
128x/64x Default = ‘0’.
Oversampling ratio is 128 when this bit is ‘1’ and 64 when this bit is ‘0’.
CAL (System calibration enable)
Default = ‘0’.
Setting this bit to ‘1’ will initiate calibration.
This bit is automatically reset to ‘0’ following calibration.
Change_sign (Change Sign enable)
Default = ‘0’.
A ‘1’ will interchange the analog input paths within each channel resulting in a phase inversion
of the analog signal. This bit applies to both channels.
_LR/LL (Left-Right output disable) Default = ‘0’.
If this bit is ‘0’, SDATA1 will output the Left and Right channel data from the sdata1 source and
SDATA2 will output the Left and Right channel data from the sdata2 source as described else-
where in the data sheet.
If this bit is set to ‘1’, the Left channel data from sdata1 source and sdata2 source (stored in
Audio port register) will be sent out in SDATA1. SDATA2 will output all the Right channel data.
76543210
fstart gndcal aapd adpd 1bit
00000
76 5 43210
128x/64x cal change_sign _LR/LL _hpen s/_m DFS mute
00 0 00000
CS5396 CS5397
26 DS229PP2
HPEN (HP enable) Default = ‘0’.
The highpass filter will be disabled when _HPEN = ‘1’. The highpass filter will be automatically
enabled following calibration.
S/_M (Slave / Master mode) Default = ‘0’.
In master mode, LRCK, and SCLK are outputs. In slave mode, LRCK and SCLK are inputs.
This bit is ignored when sdata1 is used as input port in “fir2in” or “psychoin” mode (refer to Dig-
ital control & Tag register and Appendix B).
DFS (Digital Format Select)Default = ‘0’.
Output of serial data complies with I2S standard when DFS is 1. Out-
put of serial data is Left Justified when DFS is 0.
MUTE Default = ‘0’.
Data at SDATA1 and SDATA2 is always ‘0’ when this set to ‘1’.
Audio port (address 00000011)
24bit(SDATA1) Default = ‘1’.
A ‘1’ enables the serial audio port 1 to transmit the 24-bit high precision output.
This bit must be set to ‘0’ to enable other SDATA1 output options.
24bit(SDATA2) Default = ‘0’.
A ‘1’ enables the serial audio port 2 to transmit 24-bit high precision output. This bit must be set
to ‘0’ to enable other SDATA2 output options.
psycho(SDATA1) Default = ‘0’.
psychoacoustic output will be the data at the serial audio port 1 if this bit is ‘1’ and all other bits
of the port are set to ‘0’.
psycho(SDATA2) Default = ‘0’.
psychoacoustic output will be the data at the serial audio port 2 if this bit is ‘1’ and all other bits
of the port are set to ‘0’.
psel18/_16(Psycho 18bit or 16bit)
Default = ‘0’.
This bit indicates the number of output bit if the psychoacoustic filter is chosen as output. A ‘0’
here allows 16 bits output whereas a ‘1’ allows 18 bits output as long as “psel20/_16” is ‘0’.
psel20/_16(Psycho 20bit)
Default = ‘0’.
This bit has the highest priority when setting the number of output bit of psychoacoustic filter. If
this bit is ‘1’, the output is set to 20-bit regardless of the status of “psel18/_16”.
LGD(sdata1) Default = ‘0’.
24-bit low-group-delay filter output will go through a highpass filter if “_hpen” bit in the Mode
register is ‘0’. The LGD output will be the data at the serial audio port 1 if this bit is ‘1’ and all
other bits of the port set to ‘0’.
LGD(sdata2) Default = ‘1’.
76543210
24bit
(sdata1) 24bit
(sdata2) psycho
(sdata1) psycho
(sdata2) psel18/_16 psel20/_16 lgd
(sdata1) lgd
(sdata2)
10000001
CS5396 CS5397
DS229PP2 27
24-bit low-group-delay filter output will go through a high passfilter if “_hpen” bit in the Mode
register is ‘0’. If “_hpen” is ‘1’, data at the serial audio port will derive directly from the LGD filter
output.
If more than 1 bit is set for sdata2, low-group-delay filter output will be selected for output at the
port.
Test Mode 0(address 00000100)
aoverflow A ‘1’ indicates an overflow condition occurs in the modulator. This bit is reset by reading the
register.
doverflow A ‘1’ indicates an overflow condition occurs in the decimation filter. This bit is reset by reading
the regi ster.
fir1_en(sdata) Default = ‘0’.
Test purpose only.
fir1L_R(fir1 L channel enable)
Default = ‘0’.
Test purpose only.
_psydither(psychoacoustic filter dither disable)
Default = ‘0’.
A ‘0’ means adding dither in the psychoacoustic filter.
dstart1, dstart2(dstart control bits)
Default = ‘00’.
Test purpose only.
Test Mode 1(add 00000101)
FOR FACTORY USE ONLY
Chip Address (address 00000110)
caddr(6-0) (chip address (bit6 to bit0))
Default = ‘0000000’.
This is used to store the programmable chip address for I2C and SPI mode.
When more than 1 device are connected to the I2C or SPI buses and using chip address is nec-
essary, chip address set up is done by:
1) Hold the SDATA1 pin of every chip to ‘1’ during power up.
76543210
aoverflow doverflow fir1_en fir1(LRCK) _psydither dstart1 dstart0
0000000
76543210
test mode. reserved for factory use only
76543210
caddr6 caddr5 caddr4 caddr3 caddr2 caddr1 caddr0
0000000
CS5396 CS5397
28 DS229PP2
2) Release the SDATA1 pin of the chip that is going to be programmed with chip address.
3) Send chip address and “addren”=’1’ (in Register 7) through the serial control port. (The re-
maining devices will not repond to this request.)
4) Repeat step 2) and step 3) for to other chips one-by-one. (SDATA1 output is tri-stated until
it is released from pull up.)
Digital Control & Peak Signal Level (address 00000111)
addren(chip address enable)
Default = ‘0’.
When this bit is ‘0’, no chip address comparison is done. The chip will response to all the request
from Control Port.
When this bit is ‘1’, the chip responds to the µC only if the chip address from the µC matches
the chip address stored in “caddr(6-0)”.
pken(PEAK enable) Default = ‘0’.
PSL bits calculation is based on the high precision 24-bit output.
PSL bits output follows the serial audio port that sends out 24-bit data.
If this bit is disabled, the PSL bits location on the output stream will be replaced by zeros.
pkupdate( PEA K upda te)
Default = ‘0’.
A ‘0’ to ‘1’ transition will load the peak value (since the last update) to the appropriate serial au-
dio port. The internal peak register will then reset to ‘0’.
hr/_bg(PEAK display format)
Default = ‘0’.
High resolution tag format (hr/_bg=’1’) converts the 24-bit decimation filter output into 1 dB step.
Bar Graph tag format (hr/_bg=’0’) allows LCD display format of the 24-bit output with 8 discrete
values.
ddpd(digital filter power down enable)
Default = ‘0’.
The digital filter and serial audio port is in power down mode when ddpd = ‘1’.
fir2in(external fir2 input enable)
Default = ‘0’.
Input of 2nd stage decimation filter is taken from the sdata2 port. The input data will be deci-
mated by 2 and then output to sdata1 of serial audio port.
psychoin (external psychoacoustic filter input enable)
Default = ‘0’.
Input of psychoacoustic filter is taken from the sdata2 port. The 24-bit input data will be truncat-
ed in psychoacoustic filter to the chosen output word length and then output to sdata1 of serial
audio port.
76543210
ADDREN pken pkupdate hr/_bg ddpd fir2in psychoin
0 000 000
CS5396 CS5397
DS229PP2 29
R_cal_coeff (address 00001000 - 00001010)
Default = ‘0000 0000 0000 0000 0100 0000’. (represents 1)
The right channel calibration factor is stored in these registers with MSB in bit 7 of register ad-
dress 000 0101 0.
This value is updated after every calibration cycle.
User can read from or write to this calibration factor through the serial control port.
L_cal_coeff (address 00001011 - 00001101)
Default = ‘0000 0000 0000 0000 0100 0000’. (represents 1)
The left channel calibration factor is stored in these registers with MSB in bit 7 of register ad-
dress 000 0110 1.
This value is updated after every calibration cycle.
User can read from or write to this calibration factor through the serial control port.
L_offset (address 00001110)
Default = ‘0000 0000 ’.
User can read or write this offset through the serial control port.
R_offset (address 00001111)
Default = ‘0000 0000 ’.
User can read or write this offset through the serial control port.
76543210
ralpha
(bit7) ralpha
(bit6) ralpha
(bit5) ralpha
(bit4) ralpha
(bit3) ralpha
(bit2) ralpha
(bit1) ralpha
(bit0)
00000000
ralpha
(bit15) ralpha
(bit14) ralpha
(bit13) ralpha
(bit12) ralpha
(bit11) ralpha
(bit10) ralpha
(bit9) ralpha
(bit8)
00000000
ralpha
(bit23) ralpha
(bit22) ralpha
(bit21) ralpha
(bit20) ralpha
(bit19) ralpha
(bit18) ralpha
(bit17) ralpha
(bit16)
01000000
76543210
lalpha
(bit7) lalpha
(bit6) lalpha
(bit5) lalpha
(bit4) lalpha
(bit3) lalpha
(bit2) lalpha
(bit1) lalpha
(bit0)
00000000
lalpha
(bit15) lalpha
(bit14) lalpha
(bit13) lalpha
(bit12) lalpha
(bit11) lalpha
(bit10) lalpha
(bit9) lalpha
(bit8)
00000000
lalpha
(bit23) lalpha
(bit22) lalpha
(bit21) lalpha
(bit20) lalpha
(bit19) lalpha
(bit18) lalpha
(bit17) lalpha
(bit16)
01000000
76543210
los(bit13) los(bit12) los(bit11) los(bit10) los(bit9) los(bit8) los(bit7) los(bit6)
00000000
76543210
ros(bit13) ros(bit12) ros(bit11) ros(bit10) ros(bit9) ros(bit8) ros(bit7) ros(bit6)
00000000
CS5396 CS5397
30 DS229PP2
Psycho coeff (address 00010000 - 00011000)
H1 Default = ‘1101 1010’.
H2 Default = ‘0011 0101’.
H3 Default = ‘1100 0010’.
H4 Default = ‘0100 0011’.
H5 Default = ‘1100 1011’.
H6 Default =0010 0011’.
H7 Default =1110 1100’.
H? Default =0000 1001’.
H8 Default =1111 1111’.
Psychoacoustic filter coefficients.
2’s complement representation. 4 MSB bits represent left of binary point. 4 LSB represent right
of binary point. User can read or write one or all of the coefficients through the seri al control port.
76543210
pc8(bit8) pc8(bit7) pc0(bit5) pc8(bit4) pc8(bit3) pc8(bit2) pc8(bit1) pc8(bit0)
11011010
pc7(bit8) pc7(bit7) pc1(bit5) pc7(bit4) pc7(bit3) pc7(bit2) pc7(bit1) pc7(bit0)
00110101
pc6(bit8) pc6(bit7) pc2(bit5) pc6(bit4) pc6(bit3) pc6(bit2) pc6(bit1) pc6(bit0)
11000010
pc5(bit8) pc5(bit7) pc3(bit5) pc5(bit4) pc5(bit3) pc5(bit2) pc5(bit1) pc5(bit0)
01000011
pc4(bit8) pc4(bit7) pc4(bit5) pc4(bit4) pc4(bit3) pc4(bit2) pc4(bit1) pc4(bit0)
11001011
pc3(bit8) pc3(bit7) pc5(bit5) pc3(bit4) pc3(bit3) pc3(bit2) pc3(bit1) pc3(bit0)
00100011
pc2(bit8) pc2(bit7) pc6(bit5) pc2(bit4) pc2(bit3) pc2(bit2) pc2(bit1) pc2(bit0)
11101100
pc1(bit8) pc1(bit7) pc7(bit5) pc1(bit4) pc1(bit3) pc1(bit2) pc1(bit1) pc1(bit0)
00001001
pc0(bit8) pc0(bit7) pc8(bit5) pc0(bit4) pc0(bit3) pc0(bit2) pc0(bit1) pc0(bit0)
11111111
Please see Appendix C at the end of this document
CS5396 CS5397
DS229PP2 31
PIN DESCRIPTIONS
Power Supply Connections
VA - Positive Analog Power, Pin 24.
Positive analog supply. Nominally +5 volts.
VL - Positive Logic Power, Pin 23.
Positive logic supply for the analog section. Nominally +5 volts.
AGND - Analog Ground, Pin 3, 25 and 28.
Analog ground reference.
LGND - Logic Ground, Pin 22
Ground for the logic portions of the analog section.
VD - Positive Digital Power, Pin 11.
Positive supply for the digital section. Nominally +5 volts.
DGND - Digital Ground, Pin 12.
Digital ground for the digital section.
Analog Inputs
AINR-, AINR+ - Differential Right Channel Analog Inputs, Pin 26, 27.
Analog input connections for the right channel differential inputs. Nominally 4.0 Vpp
differential for full-scale digital output.
CS5396 CS5397
32 DS229PP2
AINL-, AINL+ - Differential Left Channel Analog Inputs, Pin 4,5.
Analog input connections for the left channel differential inputs. Nominally 4.0 Vpp differential
for full-scale digital output.
Analog Outputs
VCOM - Common Mode Voltage Output, Pin 2.
Nominally +2.5 volts. Requires a 100 µF electrolytic capacitor in parallel with 0.1 µF ceramic
capacitor for decoupling to AGND. Caution is required if this output is to be used to bias the
analog input buffer circuits. Refer to text.
VREF - Voltage Reference Output, Pin 1.
Nominally +4.0 volts. Requires a 470 µF electrolytic capacitor in parallel with 0.1 µF ceramic
capacitor for decoupling to AGND.
Digital Inputs
ADCTL - Analog Control Input, Pin 6.
Must be connected to DACTL. This signal enables communication between the analog and
digital circuits.
MCLKA - Analog Section Input Clock, Pin 7.
This clock is internally divided and controls the delta-sigma modulators. The required MCLKA
frequency is determined by the desired output sample rate (Fs). MCLKA of 24.576 MHz
corresponds to an Fs of 96 kHz in 64x Oversampling Mode and 48 kHz in 128x Oversampling
Mode.
MCLKD - Digital Section Input Clock, Pin 20.
MCLKD clocks the digital filter and must be connected to MCLKA. The required MCLKD
frequency is determined by the desired output sample rate (Fs). MCLKD of 24.576 MHz
corresponds to an Fs of 96 kHz in 64x Oversampling Mode and 48 kHz in 128x Oversampling
Mode.
Digital Input Pin Definitions for Stand-Alone MODE
DFS - Digital Format Select, Pin 18.
The relationship between LRCK, SCLK and SDATA is controlled by the DFS pin. When high,
the serial output data format is I2S compatible. The serial data format is left-justified when low.
PDN - Power-Down, Pin 19.
When high, the device enters power-down. Upon returning low, the device enters normal
operation. Calibration of the device is required following release of power-down.
CS5396 CS5397
DS229PP2 33
S/M - Slave or Master Mode, Pin 17.
When high, the device is configured for Slave mode where LRCK and SCLK are inputs. The
device is configured for Master mode where LRCK and SCLK are outputs when S/M is low.
CAL - Calibration, Pin 10.
Activates the calibration of the tri-level delta-sigma modulator.
Digital Pin Definitions for CONTROL-PORT MODE
CDIN - Control Port Data Input, Pin 18.
Control port data input for SPI mode.
Control port data input and output for I2C mode.
CS - Chip Select Input, Pin 19.
Control port chip select for SPI mode. The CS5396/97 monitors the state of CS during power-
up and will configure to an SPI interface if this pin is held low. Conversely, if held high, the
port will configure to a I2C interface.
CCLK - Control Port Clock Input, Pin 17.
Control port clock input pin for both I2C and SPI modes.
CAL - Calibration, Pin 10.
CAL pin is not functional in Control Port Mode and should be connected to ground.
Digital Outputs
DACTL- Digital to Analog Control Output, Pin 9.
Must be connected to ADCTL. This signal enables communication from the digital circuits to
the analog circuits.
SDATA1 - Digital Audio Data Output #1, Pin 16.
Stand-Alone Mode - The 24-bit audio data is presented MSB first, in 2’s complement format.
Control Port Mode - The 24 audio data bits are presented MSB first, in 2’s complement format.
The audio data can be followed by 8 Peak Signal Level bits which indicate the peak signal
level. The additional audio data options include; 16, 18, or 20-bit data with or without
psychoacoustically optimized dither; or the output of the Low Group Delay filter. The SDATA1
output is completely independent from SDATA2. The mode selection between Stand-Alone and
Control Port mode is determined by the state of the SDATA1 pin during power-up. A 47 k
pull-up resistor on SDATA1 will select the Control Port mode. However, the control port will
not response to CCLK and CDIN until the pull-up on the SDATA1 pin is released.
CS5396 CS5397
34 DS229PP2
SDATA2 - Digital Audio Data Output #2, Pin 15.
Stand-Alone Mode - The 24-bit low group delay audio data is presented MSB first, in 2’s
complement format.
Control Port Mode - The 24-bit low group delay audio data is presented MSB first, in 2’s
complement format. The audio data can be followed by 8 peak detect bits which indicate the
peak signal level. The additional audio data options include; the standard 24-bit word; 16, 18,
or 20-bit data with or without psychoacoustically optimized dither. The SDATA2 output is
completely independent from SDATA1.
Digital Inputs or Outputs
LRCK - Left/Right Clock, Pin 13.
LRCK determines which channel, left or right, is to be output on SDATA1 and SDATA2. In
master mode, LRCK is an output whose frequency is equal to Fs. In Slave Mode, LRCK is an
input whose frequency must be equal to Fs. Although the outputs for each channel are
transmitted at different times, Left/Right pairs represent simultaneously sampled analog inputs.
Stand-Alone Mode - The relationship between LRCK, SCLK and SDATA is controlled by the
Digital Format Select (DFS) pin.
Control Port Mode - The relationship between LRCK, SCLK and SDATA is controlled by the
control register.
SCLK - Serial Data Clock, Pin 14.
Stand-Alone Mode- Clocks the individual bits of the serial data from SDATA1 and SDATA2. In
master mode, SCLK is an output clock at 64x Fs. In slave mode, SCLK is an input which
requires a continuously supplied clock at any frequency from 48x to 128x Fs (64x is
recommended). The relationship between LRCK, SCLK and SDATA is controlled by the
Digital Format Select (DFS) pin.
Control Port Mode - Clocks the individual bits of the serial data from SDATA1 and SDATA2.
In master mode, SCLK is an output clock at 128x the output sample rate in the 128x
Oversampling Mode and 64x the output sample rate in the 64x Oversampling Mode.
In slave mode, SCLK is an input, which requires a continuously supplied clock at any
frequency from 32x to 128x the output sample rate. A 128x SCLK is preferred in the 128x
Oversampling Mode and 64x SCLK is preferred in the 64x Oversampling Mode. The
relationship between LRCK, SCLK and SDATA is controlled by the control register.
Miscellaneous
TSTO1, TSTO2 - Test Outputs, Pins 8 and 21.
These pins are intended for factory test outputs. They must not be connected to any external
component or any length of circuit trace.
CS5396 CS5397
DS229PP2 35
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 bandwidth 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 are
below the noise level and do not affect the measurement. 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 kHz. Units in decibels.
Interchannel Isolation
A measure of crosstalk between the left and right channels. Measured for each channel at the
converter’s output with no signal to the input under test and a full-scale signal applied to the
other channel. Units in decibels.
Interchannel Gain Mismatch
The gain difference between left and right channels. 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.
CS5396 CS5397
36 DS229PP2
ADDITIONAL INFORMATION
1) “Techniques to Measure and Maximize the Per-
formance of a 120 dB, 24-bit, 96 kHz A/D Inte-
grated Circuit” by Steven Harris, Steven Green
and Ka Leung. Paper presented at the 103rd
Convention of the Audio Engineering Society,
September 1997.
2) “A 120 dB Dynamic Range, 96 kHz, 24-bit An-
alog-to-Digital Converter” by Kafai Leung, Sa-
rah Zhu, Ka Leung and Eric Swanson. Paper
presented at the 102nd Convention of the Au-
dio Engineering Society, March 1997.
3) A 5 V, 118 dB Delta Sigma Analog-to-Digital
Converter for Wideband Digital Audio by Ka
Y. Leung, Eric J. Swanson, Kafai Leung, Sarah
S. Zhu. Presented at ISSCC February, 1997, pa-
per FP 13.6
4) “How to Achieve Optimum Performa nce from
Delta-Sigma A/D and D/A Converters” by
Steven Harris. Presented at the 93rd Conven-
tion of the Audio Engineering Society, October
1992.
5) “The Effects of Sampling Clock Jitter on
Nyquist Sampling Analog-to-Digital Convert-
ers, and on Oversampling Delta Sigma ADCs”
by Steven Harris. Paper presented at the 87th
Convention of the Audio Engineering Society,
October 1989.
6) “A Fifth-Order Delta-Sigma Modulator with
110 dB Audio Dynamic Range” by I. Fujimori,
K. Hamashita and E.J. Swanson. Paper present-
ed at the 93rd Convention of the Audio Engi-
neering Society, October 1992.
7) “An 18-Bit Dual-Channel Oversampling Delta-
Sigma A/D Converter, with 19-Bit Mono Ap-
plication Example” by Clif Sanchez. Paper pre-
sented at the 87th Convention of the Audio
Engineering Society, October 1989.
8) “A Stereo 16-bit Delta-Sigma A/D Converter
for Digital Audio” by D.R. Welland, B.P. Del
Signore, E.J. Swanson, T. Tanaka, K. Hamash-
ita, S. Hara, K. Takasuka. Paper presented at
the 85th Convention of the Audio Engineering
Society, November 1988.
CS5396 CS5397
DS229PP2 37
PACKAGE DIMENSIONS
F
E
G
HI
A
B
D
C
L
K
J
B
BSC1.27 0.050 BSC
C
NOM7 7 NOM
D
0.005 0.013
0.127 0.330
E
0.095 0.105
2.41 2.67
SOIC
28 pin
MILLIMETERS INCHES
MIN MAX MAXMIN
DIM
NOM
45 45 NOM
F
NOM
7 7 NOM
G
0.008 0.015
0.203 0.381
H
8
282
I
0.292 0.298
7.42 7.59
J
0.355
0.3458.76 9.02
K
0.420
0.40010.16 10.67
L
A
0.710
0.690
17.53
18.03
M
0.020
0.0130.33 0.51
M
CS5396 CS5397
38 DS229PP2xC
APPENDIX C: PSYCHOACOUSTIC FILTER
The psychoacoustic filter in the CS5396 is based on the paper: "Robert A. Wannamaker, Psychoacous-
tically Optimal Noise Shaping, Journal of the Audio Engineering Society, Vol 40, No 7/8, 1992 July/Au-
gust." The default coefficients in the CS5396 are the FIR 9-tap filter coefficients described in Table 3 of
the paper. Since the effective noise shaping function is (1-H), the CS5396 registers save the (1-H) func-
tion coefficients. Therefore, the negative of each filter coefficient is stored in the registers. Each coefficient
is represented as a binary 2’s complement number where the 4 MSB’s represent the whole number of the
coefficient and the 4 LSB’s represent the fractional portion truncated to 4 binary bits.
Default Coefficients as listed in "Robert A. Wannamaker, Psychoacoustically Optimal Noise Shaping”
a1 = 2.412
a2 = -3.370
a3 = 3.937
a4 = -4.174
a5 = 3.353
a6 = -2.205
a7 = 1.281
a8 = -0.569
a9 = 0.0847
Coefficient conversion example 1:
a1 = 2.412
a1 = (0010.0110) binary repesentation with the fractional portion truncated to 4 bits.
-a1 = -(0010.0110) binary representation
-a1 = 1101.1010 in two’s complement
this value is stored in register 10h.
Coefficient conversion example 2:
a2 = -3.370
-a2 = 3.370
-a2 = 0011.0101 binary repesentation with the fractional portion truncated to 4 bits.
-a2 = 0011.0101 in 2's complement
this value is stored in register 11h.
CS5396 CS5397
DS229PP2xC 39
PSYCHO-ACOUSTIC FILTER COEFFICIENTS
Access:
R/W in I2C and wr ite onl y in SPI
Filter coefficient a1 (address 10h)
Filter coefficient a2 (address 11h)
Filter coefficient a3 (address 12h)
Filter coefficient a4 (address 13h)
Filter coefficient a5 (address 14h)
Filter coefficient a6 (address 15h)
Filter coefficient a7 (address 16h)
Filter coefficient a8 (address 17h)
Filter coefficient a9 (address 18h)
Default:
a1 - 1101 1010
a2 - 0011 0101
a3 - 1100 0010
a4 - 0100 0011
a5 - 1100 1011
a6 - 0010 0011
a7 - 1110 1100
a8 - 0000 1001
a9 - 1111 1111
76543210
MSB BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 LSB
Smart
Analog
TM is a Trademark of Crystal Semiconductor Corporation