24-Bit, 192-kHz Stereo Audio CODEC CS4270

CS4270
24-Bit, 192-kHz Stereo Audio CODEC
D/A Features
A/D Features
 High Performance
 High Performance
–
–
–
–
105 dB Dynamic Range
-87 dB THD+N
 Selectable Serial Audio Interface Formats
–
–
–
 Multi-bit Conversion
 High-Pass Filter to Remove DC Offsets
Left-Justified up to 24 bits
I²S up to 24 bits
Right-Justified 16, and 24 bits
 Selectable Serial Audio Interface Formats
–
–
 Control Output for External Muting
Left-Justified up to 24 bits
I²S up to 24 bits
 Single-Ended Input
System Features
 Digital De-Emphasis
 Direct Interface with Logic Levels 1.8 V to 5 V
 Popguard® Technology
 Internal Digital Loopback
 Multi-bit  Conversion
 Stand-Alone or Serial Control Port Functionality
 Single-Ended Analog Architecture
 Digital Volume Control
 Supports all Audio Sample Rates from 4 kHz to
216 kHz
 Single-Ended Output
Software or
Stand-Alone
Configuration
105 dB Dynamic Range
-95 dB THD+N
 3.3- or 5-V Core Supply
VLC
1.8 V to 5 V
VD
3.3 V to 5 V
Level
Translators
Configuration
Registers
VA
3.3 V to 5 V
Internal Voltage
Reference
____
RST
PCM Serial
Audio Input
PCM Serial
Audio Output
http://www.cirrus.com
External Mute
Control
Serial
Audio
Input
Serial
Audio
Output
Mute Signals
Volume
Control
DAC
Digital
Filter
Multi-bit
Modulator
Switch-Cap
DAC and
Analog Filter
Analog Out A
(Left)
Volume
Control
DAC
Digital
Filter
Multi-bit
Modulator
Switch-Cap
DAC and
Analog Filter
Analog Out B
(Right)
High Pass
Filter
ADC
Digital
Filter
Switch-Cap
ADC
Analog Input A
(Left)
High Pass
Filter
ADC
Digital
Filter
Switch-Cap
ADC
Analog Input B
(Right)
Copyright  Cirrus Logic, Inc. 2010
(All Rights Reserved)
AUGUST '10
DS686F1
CS4270
Stand-Alone Mode Feature Set
 System Features
–
Master or Slave Serial Audio Interface
–
Single-, Double-, or Quad-Speed Operation
 D/A Features
–
Auto-Mute on Static Samples
–
44.1 kHz 50/15 s De-emphasis Available
–
Selectable Serial Audio Interface Formats
•
Left-Justified up to 24-bit
•
I²S up to 24-bit
 A/D Features
–
High-Pass Filter
–
Selectable Serial Audio Interface Formats
•
Left-Justified up to 24-bit
•
I²S up to 24-bit
Software Mode Feature Set
 System Features
–
Master or Slave Serial Audio Interface
–
Single-, Double-, or Quad-Speed Operation
–
Internal Digital Loopback Available
General Description
The CS4270 is a high-performance, integrated audio
CODEC. The CS4270 performs stereo analog-to-digital
(A/D) and digital-to-analog (D/A) conversion of up to
24-bit serial values at sample rates up to 216 kHz.
Standard 50/15 s de-emphasis is available for sampling rates of 44.1 kHz for compatibility with digital audio
programs mastered using the 50/15 s pre-emphasis
technique.
Integrated level translators allow easy interfacing between the CS4270 and other devices operating over a
wide range of logic levels.
Independently addressable high-pass filters are available for the right and left channel of the A/D. This allows
the A/D to be used in a wide variety of applications
where one audio channel and one DC measurement
channel is desired.
The CS4270 is available in a 24-pin TSSOP package
(-10° to +70° C). The CDB4270 Customer Demonstration board is also available for device evaluation and
implementation suggestions. Please refer to “Ordering
Information” on page 44 for complete ordering
information.
The CS4270’s wide dynamic range, negligible distortion, and low noise make it ideal for applications such as
DVD recorders, digital televisions, set-top boxes, and
effects processors.
 D/A Features
–
Selectable Auto-mute
–
44.1-kHz 50/15 s De-emphasis Available
–
Configurable Muting Controls
–
Volume Control
–
Selectable Serial Audio Interface Formats
•
Left-Justified up to 24-bit
•
I²S up to 24-bit
•
Right-Justified 16, and 24-bit
 A/D Features
2
–
Selectable High-Pass Filter or DC Offset
Calibration
–
Selectable Serial Audio Interface Formats
•
Left-Justified up to 24-bit
•
I²S up to 24-bit
DS686F1
CS4270
TABLE OF CONTENTS
1. PIN DESCRIPTIONS .............................................................................................................................. 4
1.1 Software Mode ................................................................................................................................ 4
1.2 Stand-Alone Mode ........................................................................................................................... 5
2. DIGITAL I/O PIN CHARACTERISTICS .................................................................................................. 6
3. TYPICAL CONNECTION DIAGRAM ..................................................................................................... 7
4. CHARACTERISTICS AND SPECIFICATIONS ...................................................................................... 8
SPECIFIED OPERATING CONDITIONS ............................................................................................... 8
ABSOLUTE MAXIMUM RATINGS ......................................................................................................... 8
DAC ANALOG CHARACTERISTICS ..................................................................................................... 9
DAC COMBINED INTERPOLATION & ANALOG FILTER RESPONSE .............................................. 10
ADC ANALOG CHARACTERISTICS ................................................................................................... 11
ADC DIGITAL FILTER CHARACTERISTICS ....................................................................................... 12
DC ELECTRICAL CHARACTERISTICS .............................................................................................. 13
DIGITAL SWITCHING CHARACTERISTICS ....................................................................................... 13
SWITCHING CHARACTERISTICS - SERIAL AUDIO INTERFACE .................................................... 14
SWITCHING CHARACTERISTICS - SOFTWARE MODE - I²C FORMAT ........................................... 17
SWITCHING CHARACTERISTICS - SOFTWARE MODE - SPI FORMAT .......................................... 18
5. APPLICATIONS ................................................................................................................................... 19
5.1 Stand-Alone Mode ......................................................................................................................... 19
5.2 Serial Control Port Mode ............................................................................................................... 21
5.3 Popguard Transient Control .......................................................................................................... 24
5.4 De-Emphasis Filter (Single-Speed Mode Only) ............................................................................ 24
5.5 Analog Connections ...................................................................................................................... 25
5.6 Mute Control .................................................................................................................................. 27
5.7 Synchronization of Multiple Devices .............................................................................................. 28
5.8 Grounding and Power Supply Decoupling .................................................................................... 28
6. SOFTWARE MODE .............................................................................................................................. 28
6.1 Software Mode - I²C Control Port .................................................................................................. 28
6.2 Software Mode - SPI Control Port ................................................................................................. 29
7. REGISTER QUICK REFERENCE ........................................................................................................ 31
8. REGISTER DESCRIPTION .................................................................................................................. 32
8.1 Device ID - Address 01h ............................................................................................................... 32
8.2 Power Control - Address 02h ........................................................................................................ 32
8.3 Mode Control - Address 03h ......................................................................................................... 33
8.4 ADC and DAC Control - Address 04h ........................................................................................... 34
8.5 Transition Control - Address 05h ................................................................................................... 35
8.6 Mute Control - Address 06h .......................................................................................................... 36
8.7 DAC Channel A Volume Control - Address 07h ............................................................................ 36
8.8 DAC Channel B Volume Control - Address 08h ............................................................................ 37
9. FILTER PLOTS
................................................................................................................................ 38
10. PARAMETER DEFINITIONS .............................................................................................................. 42
11. PACKAGE DIMENSIONS .................................................................................................................. 43
THERMAL CHARACTERISTICS .......................................................................................................... 43
12. ORDERING INFORMATION .............................................................................................................. 44
13. REVISION HISTORY .......................................................................................................................... 44
DS686F1
3
CS4270
1. PIN DESCRIPTIONS
1.1
Software Mode
SDIN
LRCK
MCLK
SCLK
VD
DGND
SDOUT
VLC
SDA/CDOUT
SCL/CCLK
AD0/CS
AD1/CDIN
Pin Name
#
1
24
2
23
3
22
4
21
5
20
6
19
7
18
8
17
9
16
10
15
11
14
12
13
MUTEB
AOUTB
AOUTA
MUTEA
AGND
VA
FILT+
VQ
AINB
AINA
RST
AD2
Pin Description
SDIN
1 Serial Audio Data Input (Input) - Input for two’s complement serial audio data.
LRCK
2
MCLK
3 Master Clock (Input) - Clock for the delta-sigma modulator and the digital filters.
SCLK
4 Serial Bit Clock (Input/Output) - Serial bit clock for the serial audio interface.
VD
5 Digital Power (Input) - Positive power for the digital section.
DGND
6 Digital Ground (Input) - Ground reference for the digital section.
SDOUT
7 Serial Audio Data Output (Output) - Output for two’s complement serial audio data.
VLC
8 Serial Control Port Power (Input) - Positive power for the Serial Control Port.
Left Right Clock (Input/Output) - Determines which channel, left or right, is currently active on the serial audio
data line. The frequency of the left/right clock must be at the audio sample rate, Fs.
Control Data (Input/Output) - SDA is a data I/O line in I²C Mode. CDOUT is the output data line for the
SDA/CDOUT 9 Serial
Serial Control Port in SPI format.
SCL/CCLK
Serial Control Port Clock (Input) - SCL is the serial input Clock for the Serial Control Port in I²C format. CCLK
10 is
the serial input Clock for the Serial Control Port in SPI format.
AD0/CS
Bit 0 (I²C)/Serial Control Port Chip Select (SPI) (Input) - AD0 is a chip address pin in I²C format.
11 Address
CS is the chip select signal for SPI format.
AD1/CDIN
12
AD2
13 Address Bit 2 (I²C) (Input) - AD2 is a chip address pin in I²C format.
RST
14
AINA
AINB
15
Analog Audio Input (Input) - Analog inputs to the ADC.
16
VQ
17 Quiescent Voltage (Output) - Filter connection for the internal quiescent voltage.
FILT+
18 Positive Voltage Reference (Output) - Positive reference voltage for the internal sampling circuits.
VA
19 Analog Power (Input) - Positive power for the analog section.
AGND
20 Analog Ground (Input) - Ground reference for the analog section.
MUTEA
MUTEB
21 Mute Control (Output) - Mute control signal used to control the state of the optional external analog muting
24 circuitry. See Section 5.6 on page 27.
AOUTA
AOUTB
22
Analog Audio Output (Output) - Analog outputs from the DAC.
23
4
Address Bit 1 (I²C)/Serial Control Data (Input) - AD1 is a chip address pin in I²C Mode. CDIN is the input
data line for the Serial Control Port in SPI format.
Reset (Input) - Input for resetting all internal registers to their default settings and for placing the device in a
low-power mode.
DS686F1
CS4270
1.2
Stand-Alone Mode
SDIN
LRCK
MCLK
SCLK
VD
DGND
SDOUT
VLC
M1
M0
I²S/LJ
MDIV1
Pin Name
#
1
24
2
23
3
22
4
21
5
20
6
19
7
18
8
17
9
16
10
15
11
14
12
13
MUTEB
AOUTB
AOUTA
MUTEA
AGND
VA
FILT+
VQ
AINB
AINA
RST
MDIV2
Pin Description
SDIN
1
Serial Audio Data Input (Input) - Input for two’s complement serial audio data.
LRCK
2
Left Right Clock (Input/Output) - Determines which channel, Left or Right, is currently active on the
serialaudio data line. The frequency of the left/right clock must be at the audio sample rate, Fs.
MCLK
3
Master Clock (Input) - Clock source for the delta-sigma modulator and digital filters.
SCLK
4
Serial Bit Clock (Input/Output) - Serial bit clock for the serial audio interface.
VD
5
Digital Power (Input) - Positive power for the digital section.
DGND
6
Digital Ground (Input) - Ground reference for the digital section.
SDOUT
(M/S)
7
Serial Audio Data Output (Output) - Output for two’s complement serial audio data. This pin must be
pulled up or down through a 47-k resistor to select Master or Slave Mode.
VLC
8
Serial Control Port Power (Input) - Positive power for the Serial Control Port.
M1
M0
9
10
Mode Selection (Input) - Determines the system sampling frequency range of the device.
I²S/LJ
11
Serial Audio Interface Select (Input) - Selects either the Left-Justified or I²S format for the Serial Audio
Interface.
MDIV1
MDIV2
12
13
MCLK Divide (Input) - Configures the device to divide MCLK by 1, 1.5, 2, or 4.
RST
14
Reset (Input) - Input for resetting all internal registers to their default settings and for placing the device
in a low-power mode.
AINA
AINB
15
16
Analog Input (Input) - Analog inputs to the ADC.
VQ
17
Quiescent Voltage (Output) - Filter connection for the internal quiescent voltage
FILT+
18
Positive Voltage Reference (Output) - Positive reference voltage for the internal sampling circuits.
VA
19
Analog Power (Input) - Positive power for the analog section.
AGND
20
Analog Ground (Input) - Ground reference for the analog section.
MUTEA
MUTEB
21
24
Mute Control (Output) - Mute control signal used to control the state of the optional external analog muting circuitry. See Section 5.6 on page 27.
AOUTA
AOUTB
22
23
Analog Audio Output (Output) - Analog outputs for the DAC.
DS686F1
5
CS4270
2. DIGITAL I/O PIN CHARACTERISTICS
The level for each input is set by its corresponding power supply and should not exceed the maximum ratings.
Power
Pin
Supply Number
Software Mode
VLC
Pin Name
I/O
Driver
Receiver
9
SDA/CDOUT
Input/Output
1.8 V-5.0 V, Open Drain
1.8 V-5.0 V, with hysteresis
10
SCL/CCLK
Input
-
1.8 V-5.0 V, with hysteresis
11
AD0/CS
Input
-
1.8 V-5.0 V
12
AD1/CDIN
Input
-
1.8 V-5.0 V
13
AD2
Input
-
1.8 V-5.0 V
M1
Input
-
1.8 V-5.0 V
Stand-Alone Mode
9
VLC
10
M0
Input
-
1.8 V-5.0 V
11
I²S/LJ
Input
-
1.8 V-5.0 V
12
MDIV1
Input
-
1.8 V-5.0 V
13
MDIV2
Input
-
1.8 V-5.0 V
1
SDIN
Input
-
3.3 V-5.0 V
2
LRCK
Input/Output
3.3 V-5.0 V, CMOS
3.3 V-5.0 V
3
MCLK
Input
-
3.3 V-5.0 V
4
SCLK
Input/Output
3.3 V-5.0 V, CMOS
3.3 V-5.0 V
7
SDOUT
Output
3.3 V-5.0 V, CMOS
-
14
RST
Input
-
1.8 V-5.0 V
21
MUTEA
Output
3.3 V-5.0 V, CMOS
-
24
MUTEB
Output
3.3 V-5.0 V, CMOS
-
All Modes
VD
VA
Table 1. Digital I/O Pin Power Rails
6
DS686F1
CS4270
3. TYPICAL CONNECTION DIAGRAM
+3.3 V to 5 V
1
0.1 µF
1 µF
0.1 µF
1 µF
5.1 
1
2
VD
VA
FILT+
47 µF
+3.3 V to 5 V
GND or VD
0.1 µF
47 k
AGND
10 µF
0.1 µF
SDOUT (M/ S)
SDIN
VQ
Analog Input
Audio Data
Processor
AINA
Network
AINB
CS4270
MCLK
Timing Logic
and
Clocks
SCLK
LRCK
AD2 (MDIV1)
AD1/CDIN (MDIV2)
Power
Down
and Mode
Settings
AD0 / CS (I2S/LJ)
SDA/CDOUT (M1)
SCL/CCLK (M0)
(Control Port)
3
2 k
2 k
and Mute
VLC
DGND
0.1 µF
1.
Network
AOUTB
MUTEB
3
+1.8 V to 5 V
Analog Output
MUTEA
AOUTA
RST
If using separate supplies for
VA and VD, 5.1 resistor not
needed. See "Grounding and
Power Supply Decoupling."
2.
In Stand-Alone mode, use a
47 kO pull-down to select
Slave Mode or 47 kO pull-up to
VD to select Master Mode. See
"Master/Slave Mode Selection."
3.
Use pull-up resistors in Software
Mode. In Stand-Alone Mode, use
pull-up or pull-down. See "Mode
Selection & De-Emphasis."
Figure 1. CS4270 Typical Connection Diagram
DS686F1
7
CS4270
4. CHARACTERISTICS AND SPECIFICATIONS
SPECIFIED OPERATING CONDITIONS
AGND = DGND= 0 V; all voltages with respect to ground.
Parameters
DC Power Supplies:
Symbol
Min
Nom
Max
Units
VA
VD
VLC
TA
3.14
3.14
1.71
-40
5.0
3.3
3.3
-
5.25
5.25
5.25
+85
V
V
V
C
Analog
Digital
Serial Control Port
Ambient Operating Temperature (Power Applied)
ABSOLUTE MAXIMUM RATINGS
AGND = DGND = 0 V, All voltages with respect to ground.(Note 1)
Parameter
DC Power Supplies:
Analog
Digital
Serial Control Port
Symbol
Min
Typ
Max
Units
VA
VD
VLC
-0.3
-0.3
-0.3
-
+6.0
+6.0
+6.0
V
V
V
Iin
-10
-
10
mA
VIN
AGND-0.7
-
VA+0.7
V
VIND-C
VIND-D
-0.3
-0.3
-
VLC+0.3
VD+0.3
V
V
Ambient Operating Temperature (Power Applied)
TAC
-50
-
+95
C
Storage Temperature
Tstg
-65
-
+150
C
Input Current
(Note 2)
Analog Input Voltage
Digital Input Voltage
Serial Control Port
Digital
Notes: 1. Operation beyond these limits may result in permanent damage to the device. Normal operation is not
guaranteed at these extremes.
2. Any pin except supplies. Transient currents of up to ±100 mA on the analog input pins will not cause
SCR latch-up.
8
DS686F1
CS4270
DAC ANALOG CHARACTERISTICS
Test Conditions (unless otherwise specified): VD = VL = 3.3 V, AGND = DGND = 0 V; TA = +25° C; Full-Scale Output Sine Wave, 997 Hz (Note 3). Decoupling capacitors, filter capacitors, and recommended output filter as shown
in Figure 1 on page 7. Fs = 48/96/192 kHz; Synchronous Mode; Test load RL = 3 k, CL = 10 pF (see Figure 2).
Measurement Bandwidth 10 Hz to 20 kHz.
VA = 5 V
Parameter
Dynamic Range
18 to 24 bit
A-weighted
unweighted
A-weighted
unweighted
16 Bit
Total Harmonic Distortion + Noise
18 to 24 bit
0 dB
-20 dB
-60 dB
0 dB
-20 dB
-60 dB
16 Bit
VA = 3.3 V
Symbol
Min
Typ
Max
Min
Typ
Max
Unit
DR
99
96
90
87
105
102
96
93
-
97
94
90
87
103
100
96
93
-
dB
dB
dB
dB
-
-87
-82
-42
-85
-76
-36
-83
-81
-
-
-83
-80
-40
-81
-76
-36
-79
-77
-
dB
dB
dB
dB
dB
dB
THD+N
DAC Performance across Full VA Range
Parameter
Symbol
Interchannel Isolation
Min
Typ
Max
Unit
-
100
-
dB
-
0.1
0.25
dB
-100
-
+100
ppm/°C
(1 kHz)
DC Accuracy
Interchannel Gain Mismatch
Gain Drift
Analog Output
Full Scale Output Voltage
0.6•VA
0.65•VA
0.7•VA
Vpp
IOUTmax
-
10
-
A
Max AC-Load Resistance (see Figure 3)
RL
-
3
-
k
Max Load Capacitance (see Figure 3)
CL
-
100
-
pF
ZOUT
-
100
-

Max DC Current draw from AOUTA or AOUTB
Output Impedance of AOUTA and AOUTB
Note:
3. One LSB of triangular PDF dither added to data.
125
V
out
AOUTx
R
L
AGND
C
L
Capacitive Load -- C (pF)
L
3.3 µF
100
75
25
2.5
3
Figure 2. Output Test Load
DS686F1
Safe Operating
Region
50
5
10
15
20
Resistive Load -- RL (k )
Figure 3. Maximum Loading
9
CS4270
DAC COMBINED INTERPOLATION & ANALOG FILTER RESPONSE
The filter characteristics have been normalized to the sample rate (Fs) and can be referenced to the desired sample rate by multiplying the given characteristic by Fs. (See Note 4)
Parameter
Symbol
Min
Typ
Max
Unit
0
0
-
.35
.4992
Fs
Fs
Frequency Response 10 Hz to 20 kHz
-.175
-
+.01
dB
StopBand
.5465
-
-
Fs
Single-Speed Mode
Passband (Note 5)
StopBand Attenuation
to -0.1 dB corner
to -3 dB corner
(Note 6)
50
-
-
dB
-
10/Fs
-
s
Fs = 32 kHz
Fs = 44.1 kHz
Fs = 48 kHz
-
-
+1.5/+0
+.05/-.25
-.2/-.4
dB
dB
dB
to -0.1 dB corner
to -3 dB corner
0
0
-
.22
.501
Fs
Fs
-.15
-
+.15
dB
.5770
-
-
Fs
Group Delay
De-emphasis Error (Note 8)
tgd
Double-Speed Mode
Passband (Note 5)
Frequency Response 10 Hz to 20 kHz
StopBand
StopBand Attenuation
(Note 6)
55
-
-
dB
-
5/Fs
-
s
0
0
-
0.110
0.469
Fs
Fs
Frequency Response 10 Hz to 20 kHz
-.12
-
+0
dB
StopBand
0.7
-
-
Fs
Group Delay
tgd
Quad-Speed Mode
Passband (Note 5)
StopBand Attenuation
to -0.1 dB corner
to -3 dB corner
(Note 6)
Group Delay
tgd
51
-
-
dB
-
2.5/Fs
-
s
Notes: 4. Amplitude vs. Frequency plots of this data are available in Section 9. “Filter Plots” on page 38. See
Figures 23 through 46.
5. Response is clock dependent and will scale with Fs.
6. For Single-Speed Mode, the Measurement Bandwidth is 0.5465 Fs to 3 Fs.
For Double-Speed Mode, the Measurement Bandwidth is 0.577 Fs to 1.4 Fs.
For Quad-Speed Mode, the Measurement Bandwidth is 0.7 Fs to 1 Fs.
7. De-emphasis is available only in Single-Speed Mode.
10
DS686F1
CS4270
ADC ANALOG CHARACTERISTICS
Test Conditions (unless otherwise specified): VD = VL = 3.3 V, DGND = AGND = 0 V; TA = 25° C; 997 Hz Input
Sine Wave. Figure 15 on page 26 shows the test circuit; Fs = 48/96/192 kHz; Synchronous Mode; Measurement
Bandwidth 10 Hz to 20 kHz.
Dynamic Performance
Single-Speed Mode
Dynamic Range
Total Harmonic Distortion + Noise
Double-Speed Mode
VA = 5 V
Fs = 48 kHz Symbol
A-weighted
unweighted
(Note 8)
-1 dB
THD+N
-20 dB
-60 dB
VA = 3.3 V
Min
Typ
Max
Min
Typ
Max
Unit
99
96
105
102
-
96
93
102
99
-
dB
dB
-
-95
-82
-42
-90
-
-
-92
-79
-39
-87
-
dB
dB
dB
99
96
-
105
102
99
-
96
93
-
102
99
96
-
dB
dB
dB
-
-95
-82
-42
-93
-90
-
-
-92
-79
-39
-89
-87
-
dB
dB
dB
dB
99
96
-
105
102
99
-
96
93
-
102
99
96
-
dB
dB
dB
-
-95
-82
-42
-93
-90
-
-
-92
-79
-39
-89
-87
-
dB
dB
dB
dB
Fs = 96 kHz
Dynamic Range
A-weighted
unweighted
40 kHz bandwidth unweighted
Total Harmonic Distortion + Noise
(Note 8)
-1 dB
-20 dB
-60 dB
40 kHz bandwidth unweighted
Quad-Speed Mode
Fs = 192 kHz
Dynamic Range
A-weighted
unweighted
40 kHz bandwidth unweighted
Total Harmonic Distortion + Noise
(Note 8)
-1 dB
-20 dB
-60 dB
40 kHz bandwidth
-1 dB
THD+N
THD+N
Dynamic Performance - All Sampling Speed Modes
Parameter
Interchannel Isolation
DC Accuracy
Interchannel Gain Mismatch
Gain Error
Gain Drift
Analog Input Characteristics
Full-Scale Input Voltage
Input Impedance
Note:
Min
-
Typ
100
Max
-
Unit
dB
-3
-
0.1
100
+3
-
dB
%
ppm/°C
0.53*VA
-
0.56*VA
300
0.58*VA
-
Vpp
k
8. Referred to the typical full-scale input voltage.
DS686F1
11
CS4270
ADC DIGITAL FILTER CHARACTERISTICS
Measurement Bandwidth is 10 Hz to 20 kHz unless otherwise specified. (Note 9)
Parameter
Symbol
Min
Typ
Max
Unit
(Note 10)
0
-
0.49
Fs
-
-
0.035
dB
(Note 10)
0.57
-
-
Fs
70
-
-
dB
-
12/Fs
-
s
0
-
0.49
Fs
-
-
0.05
dB
0.56
-
-
Fs
69
-
-
dB
-
9/Fs
-
s
0
-
0.26
Fs
-
-
0.05
dB
0.50
-
-
Fs
60
-
-
dB
-
5/Fs
-
s
Single-Speed Mode
Passband
(-0.1 dB)
Passband Ripple
Stopband
Stopband Attenuation
Group Delay
tgd
Double-Speed Mode
Passband
(-0.1 dB)
(Note 10)
Passband Ripple
Stopband
(Note 10)
Stopband Attenuation
Group Delay
tgd
Quad-Speed Mode
Passband
(-0.1 dB)
(Note 10)
Passband Ripple
Stopband
(Note 10)
Stopband Attenuation
Group Delay
tgd
High-Pass Filter Characteristics
Frequency Response
Phase Deviation
-3.0 dB
-0.13 dB
(Note 11)
-
1
20
-
Hz
Hz
@ 20 Hz
(Note 11)
-
10
-
deg
-
-
0
dB
Passband Ripple
Notes: 9. Plots of this data are contained in Section 9. “Filter Plots” on page 38. See Figures 23 through 46.
10. The filter frequency response scales precisely with Fs.
11. Response shown is for Fs equal to 48 kHz. Filter characteristics scale with Fs.
12
DS686F1
CS4270
DC ELECTRICAL CHARACTERISTICS
TA = 25° C; AGND = DGND = 0 V, all voltages with respect to 0 V; MCLK = 12.288 MHz; Master Mode).
Parameter
Symbol
Min
Typ
Max
Unit
VA = 5 V
VA = 3.3 V
VD, VLC = 5 V
VD, VLC = 3.3 V
IA
IA
ID
ID
-
37
24
32
13
42
30
38
20
mA
mA
mA
mA
VA = 5 V
VD, VLC = 5 V
IA
ID
-
70
3
-
A
A
Normal Operation
Normal Operation
Power-Down Mode (Note 12)
-
-
224
345
365
270
400
-
mW
mW
W
PSRR
-
55
-
dB
VQ
Power Supply
Power Supply Current
(Normal Operation)
Power Supply Current
(Power-Down Mode) (Note 12)
Power Consumption
VA = 5 V, VD = VLC= 3.3 V
VA = 5 V, VD = VLC = 5 V
Power Supply Rejection Ratio(1 kHz)
(Note 13)
Common Mode Voltage
Nominal Common Mode Voltage
-
VA/2
-
VDC
Maximum DC Current Source/Sink from VQ
-
1
-
A
VQ Output Impedance
-
25
-
k
Positive Voltage Reference
FILT+ Nominal Voltage
-
VA
-
VDC
Maximum DC Current Source/Sink from FILT+
FILT+
-
10
-
A
FILT+ Output Impedance
-
10
-
k
-
3
-
mA
Mute Control
Maximum MUTEA & MUTEB Drive Current
Notes: 12. Power Down Mode is defined as RST = Low with all clocks and data lines held static.
13. Valid with the recommended capacitor values on FILT+ and VQ as shown in the Typical Connection
Diagram.
DIGITAL SWITCHING CHARACTERISTICS
Symbol
Min
Typ
Max
Units
High-Level Input Voltage
Parameter (Note 14)
Serial Audio Interface
Serial Control Port
VIH
0.7xVD
0.7xVLC
-
-
V
V
Low-Level Input Voltage
Serial Audio Interface
Serial Control Port
VIL
-
-
0.2xVD
0.2xVLC
V
V
High-Level Output Voltage at Io = 2 mA
Serial Audio Interface
Serial Control Port
MUTEA, MUTEB
VOH
VD - 1.0
VLC - 1.0
VA - 1.0
-
-
V
V
V
Low-Level Output Voltage at Io = 2 mA
Input Leakage Current
VOL
-
-
0.4
V
Iin
-10
-
10
A
Notes: 14. Serial Audio Port signals include: SCLK, LRCK, SDOUT, SDIN
Serial Control Port signals include: SDA/CDOUT, SCL/CCLK, AD1/CDIN, AD0/CS, RST
DS686F1
13
CS4270
SWITCHING CHARACTERISTICS - SERIAL AUDIO INTERFACE
Logic "0" = DGND = AGND = 0 V; Logic "1" = VD, CL = 20 pF.
Parameter
Sample Rate
Single-Speed Mode
Double-Speed Mode
Quad-Speed Mode
Symbol
Min
Typ
Max
Unit
Fs
Fs
Fs
4
50
100
-
54
108
216
kHz
kHz
kHz
fmclk
fmclk
1.024
1.024
-
55.296
55.296
MHz
MHz
40
50
60
ns
-
50
-
%
-
1
----------------- 64 Fs
-
s
-
50
-
%
MCLK Specifications
MCLK Frequency
(Note 15)
Stand-Alone Mode
Serial Control Port Mode
MCLK Duty Cycle
Master Mode
LRCK Duty Cycle
SCLK Period (Note 16)
tsclkw
SCLK Duty Cycle
SCLK falling to LRCK edge
tmslr
-20
-
20
ns
SCLK falling to SDOUT valid
tsdo
-
-
32
ns
SDIN valid to SCLK rising setup time
tsdis
16
-
-
ns
SCLK rising to SDIN hold time
tsdih
20
-
-
ns
40
50
60
%
tsclkw
1
-------------------- 128 Fs
-
-
s
tsclkw
1
----------------- 64 Fs
-
-
s
tsclkw
1
----------------- 64 Fs
45
-
-
s
50
55
ns
Slave Mode
LRCK Duty Cycle
SCLK Period
(Note 15)
Single-Speed Mode
Double-Speed Mode
Quad-Speed Mode
SCLK Duty Cycle
SCLK falling to LRCK edge
tslrd
-20
-
20
ns
SDOUT valid before SCLK rising
tstp
10
-
-
ns
SDOUT valid after SCLK rising
thld
5
-
-
ns
SDIN valid to SCLK rising setup time
tsdis
16
-
-
ns
SCLK rising to SDIN hold time
tsdih
20
-
-
ns
Notes: 15. In Control Port Mode, MCLK Frequency, and Functional Mode Select bits must be configured according
to Table 7 on page 22, Table 9 on page 33, and Table 13 on page 35.
16. tsclkw = tsclkh + tsclkl in Figures 5 and 7.
14
DS686F1
CS4270
LRCK output
LRCK input
t mslr
t slrd
SCLK output
SCLK input
t sclkh
t sdo
SDOUT
MSB
MSB-1
MSB-2
t stp t hld
MSB-3
SDOUT
Figure 4. Master Mode, Left-Justified SAI
MSB
MSB-1
Figure 5. Slave Mode, Left-Justified SAI
LRCK input
LRCK output
t slrd
tmslr
SCLK input
SCLK output
t sclkh
MSB
MSB-1
t sclkl
t stp t hld
t sdo
SDOUT
t sclkl
SDOUT
MSB-2 MSB-3
Figure 6. Master Mode, I²S SAI
MSB
Figure 7. Slave Mode, I²S SAI
t sclkw
SCLK
t
sdis
t
sdih
SDIN
Figure 8. Master and Slave Mode, SCLK/SDIN
DS686F1
15
CS4270
Channel A - Left
LRCK
Channel B - Right
SCLK
SDATA
MSB
-1 -2 -3 -4 -5
+5 +4 +3 +2 +1 LSB
MSB
-1 -2 -3 -4
+5 +4 +3 +2 +1 LSB
Figure 9. Format 0, Left-Justified up to 24-Bit Data
Channel A - Left
LRCK
Channel B - Right
SCLK
SDINx
MSB
-1 -2 -3 -4 -5
+5 +4 +3 +2 +1 LSB
MSB
-1 -2 -3 -4
+5 +4 +3 +2 +1 LSB
Figure 10. Format 1, I²S up to 24-Bit Data
LRCK
Channel
B - Right
Right Channel
Channel A - Left
SCLK
SDATA LSB
MSB
-1 -2 -3 -4 -5 -6
+6 +5 +4 +3 +2 +1 LSB
MSB
-1 -2 -3 -4 -5 -6
+6 +5 +4 +3 +2 +1 LSB
32 clocks
Figure 11. Format 2 or 3, Right-Justified 16-Bit or 24-Bit Data (Serial Control Port Mode Only)
16
DS686F1
CS4270
SWITCHING CHARACTERISTICS - SOFTWARE MODE - I²C FORMAT
Inputs: Logic ‘0’ = AGND = DGND = 0 V, Logic ‘1’ = VLC, CL = 30 pF
Parameter
Symbol
Min
Max
Unit
SCL Clock Frequency
fscl
-
100
kHz
RST Rising Edge to Start
tirs
500
-
ns
Bus Free Time Between Transmissions
tbuf
4.7
-
µs
Start Condition Hold Time (prior to first clock pulse)
thdst
4.0
-
µs
Clock Low time
tlow
4.7
-
µs
Clock High Time
thigh
4.0
-
µs
Setup Time for Repeated Start Condition
tsust
4.7
-
µs
SDA Hold Time from SCL Falling (Note 17)
thdd
0
-
µs
SDA Setup time to SCL Rising
tsud
250
-
ns
trc
-
1
µs
Rise Time of SCL and SDA
tfc
-
300
ns
Setup Time for Stop Condition
tsusp
4.7
-
µs
Acknowledge Delay from SCL Falling
tack
300
1000
ns
Fall Time SCL and SDA
Note:
17. Data must be held for sufficient time to bridge the transition time, tfc, of SCL.
RS T
t
irs
Stop
R epe ate d
Start
Start
t rd
t fd
Stop
SDA
t
buf
t
t
hdst
t
high
t fc
hdst
t susp
SCL
t
lo w
t
hdd
t sud
t ack
t sust
t rc
Figure 12. Software Mode Timing - I²C Format
DS686F1
17
CS4270
SWITCHING CHARACTERISTICS - SOFTWARE MODE - SPI FORMAT
Inputs: Logic ‘0’ = AGND = DGND = 0 V; Logic ‘1’ = VLC; CL = 20 pF.
Parameter
Symbol
Min
Max
Unit
CCLK Clock Frequency
fsclk
-
6
MHz
RST Rising Edge to CS Falling
tsrs
500
-
ns
CCLK Edge to CS Falling (Note 18)
tspi
500
-
ns
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 19)
tdh
15
-
ns
Rise Time of CCLK and CDIN (Note 20)
tr2
-
100
ns
Fall Time of CCLK and CDIN (Note 20)
tf2
-
100
ns
Transition Time from CCLK to CDOUT Valid (Note 21)
tscdov
-
100
ns
Time from CS rising to CDOUT High-Z
tcscdo
-
100
ns
Notes: 18. tspi only needed before first falling edge of CS after RST rising edge. tspi = 0 at all other times.
19. Data must be held for sufficient time to bridge the transition time of CCLK.
20. For FSCK < 1 MHz.
21. CDOUT should not be sampled during this time.
RST
t srs
CS
t spi t css
t scl
t sch
t csh
CCLK
t r2
t f2
CDIN
t dsu t
dh
Hi-Impedance
CDOUT
t scdov
t scdov
t cscdo
Figure 13. SPI Control Port Timing
18
DS686F1
CS4270
5. APPLICATIONS
5.1
Stand-Alone Mode
5.1.1
Access to Stand-Alone Mode
Reliable power-up is achieved by keeping the device in reset until the power supplies, clocks and configuration pins are stable. It is also recommended that RST be asserted if the analog or digital supplies drop
below the minimum specified operating voltages to prevent power glitch related issues.
The delay time from the release of reset until the device enters Stand-Alone Mode is 1,045 sample periods. Table 2 lists the approximate wait time for each sampling mode.
Speed Mode
Approximate Delay Time
Single-Speed
21.8 ms (48 kHz)
Double-Speed
10.9 ms (96 kHz)
Quad-Speed
5.4 ms (192 kHz)
Table 2. Approximate Delay Time from Release of RST to Entering Standalone Mode
5.1.2
Access to Master/Slave Mode
The CS4270 supports operation in either Master Mode or Slave Mode.
In Master Mode, LRCK and SCLK are outputs and are synchronously generated by the device. The LRCK
frequency is equal to Fs and the SCLK frequency is equal to 64x Fs.
In Slave Mode, LRCK and SCLK are inputs, requiring external generation that is synchronous to MCLK.
SCLK must be 48x or 64x Fs to maximize system performance.
In Stand-Alone Mode, the CS4270 enters Slave Mode when SDOUT (M/S) is pulled low through a 47 k
resistor. Master Mode is accessed by placing a 47 k pull-up to VD on the SDOUT (M/S) pin.
Configuration of clock ratios in each of these modes is outlined in Table 4.
5.1.3
System Clocking
The CS4270 operates at sampling frequencies from 4 kHz to 216 kHz. This range is divided into three
speed modes, as shown in Table 3.
Mode
Sampling Frequency
Single-Speed
4-54 kHz
Double-Speed
50-108 kHz
Quad-Speed
100-216 kHz
Table 3. Speed Modes
DS686F1
19
CS4270
5.1.4
Clock Ratio Selection
Depending on whether the CS4270 is in Master or Slave Mode, different MCLK/LRCK and SCLK/LRCK
ratios may be used. These ratios are shown in the Table 4. ‘0’ = DGND, ‘1’ = VLC.
Master Mode
Single-Speed
Double-Speed
Quad-Speed
MCLK/LRCK
SCLK/LRCK
LRCK
MDIV2
MDIV1
256
64
Fs
0
0
384 (Note 22)
64
Fs
0
1
512
64
Fs
1
0
1,024
64
Fs
1
1
128
64
Fs
0
0
192 (Note 22)
64
Fs
0
1
256
64
Fs
1
0
512
64
Fs
1
1
64
64
Fs
0
0
96 (Note 22)
64
Fs
0
1
128
64
Fs
1
0
256
64
Fs
1
1
Slave Mode
Single-Speed
Double-Speed
Quad-Speed
MCLK/LRCK
SCLK/LRCK
LRCK
MDIV2
MDIV1
256
32, 48, 64, 128
Fs
0
0
384 (Note 22)
32, 48, 64, 96
Fs
0
1
512
32, 48, 64, 128
Fs
1
0
1,024
32, 48, 64, 96
Fs
1
1
128
32, 48, 64
Fs
0
0
192 (Note 22)
32, 48, 64
Fs
0
1
256
32, 48, 64
Fs
1
0
512
32, 48, 64
Fs
1
1
64
32, 48, 64
Fs
0
0
96 (Note 22)
32, 48, 64
Fs
0
1
128
32, 48, 64
Fs
1
0
256
32, 48, 64
Fs
1
1
Table 4. Clock Ratios - Stand-Alone Mode
Note:
5.1.5
22. Once the MDIVx pins have been configured for this setting, RST must be asserted and then deasserted
before normal operation can begin. During startup, RST should remain asserted until after this selection
is made and then deasserted.
Interpolation Filter
In Stand-Alone Mode, the fast roll-off interpolation filter is used. Filter specifications can be found in Section 4. Plots of the data are contained in Section 9. “Filter Plots” on page 38.
5.1.6
High-Pass Filter
At the system level, the input circuitry driving the CS4270 may generate a small DC offset into the ADC.
The CS4270 includes one high-pass filter per channel after the decimator to remove any DC offset, which
20
DS686F1
CS4270
could result in recording a DC level, possibly yielding "clicks" when switching between devices in a multichannel system. In Stand-Alone Mode, the high-pass filter is always active and continuously subtracts a
measure of the DC offset from the output of the decimation filter.
5.1.7
Mode Selection & De-Emphasis
The sample rate, Fs, can be adjusted from 4 kHz to 216 kHz and De-emphasis, optimized for 44.1 kHz,
is available in Single-Speed Mode. In Stand-Alone Master Mode, the CS4270 must be set to the proper
mode via the mode pins, M1 and M0. In Slave Mode, the CS4270 auto-detects Speed Mode and the M0
pin becomes De-emphasis select. Stand-alone definitions of the mode pins in Master Mode are shown in
Table 5.
Mode 1
Mode 0
Mode
Sample Rate (Fs)
De-Emphasis
0
0
Single-Speed
4 kHz - 54 kHz
Off
0
1
Single-Speed
4 kHz - 54 kHz
44.1 kHz
1
0
Double-Speed
50 kHz - 108 kHz
Off
1
1
Quad-Speed
100 kHz - 216 kHz
Off
Table 5. CS4270 Stand-Alone Mode Control
5.1.8
Access to Serial Audio Interface Format
Either I²S or Left-Justified serial audio data format may be selected in Stand-Alone Mode. To use the I2S
format, tie the I²S/LJ pin to VLC during power up. To use LJ format, tie I²S/LJ to DGND during power up.
5.2
Serial Control Port Mode
5.2.1
Access to Serial Control Port Mode
Reliable power-up is achieved by keeping the device in reset until the power supplies, clocks, and configuration pins are stable. It is also recommended that RST be asserted if the analog or digital supplies drop
below the minimum specified operating voltages to prevent power glitch related issues.
After RST is released, the device is put into Serial Control Port Mode by setting the power down bit
through a SPI or I²C transaction, as described in Section 6.1 and Section 6.2.
If the transaction is not completed within 1,045 sample periods after the release of reset, the device enters
Stand-Alone Mode.
If the first Serial Control Port transaction is ongoing while the device is executing pop control, there is a
chance of generating audio transients. The details of the duration of pop control is outlined in Section 5.3.1
“Power-Up” on page 24.
When the device is Serial Control Port Mode, it can be programmed as desired. After clearing the powerdown bit, desired device functioning can start.
5.2.2
Access to Master/Slave Mode
The CS4270 supports operation in either Master Mode or Slave Mode.
•
In Master Mode, LRCK and SCLK are outputs and are synchronously generated by the device. LRCK
is equal to Fs and SCLK is equal to 64x Fs.
•
In Slave Mode, LRCK and SCLK are inputs, requiring external generation that is synchronous to MCLK.
It is recommended that SCLK be 48x or 64x Fs to maximize system performance.
DS686F1
21
CS4270
Clock-ratio configuration for each mode is outlined in the Table 11 on page 34 and Table 10 on page 33.
In Serial Control Port Mode, the CS4270 defaults to Slave Mode. The user may change this default setting
by changing the status of the FM bits in the Mode Control Register (03h).
5.2.3
System Clocking
The CS4270 operates at sampling frequencies from 4 kHz to 216 kHz. This range is divided into three
speed modes as shown in Table 6.
Mode
Sampling Frequency
Single-Speed
4-54 kHz
Double-Speed
50-108 kHz
Quad-Speed
100-216 kHz
Table 6. Speed Modes
5.2.4
Clock Ratio Selection
In Serial Control Port Master Mode, the user must configure the mode bits (MCLK_FREQ[2:0]) to set the
speed mode and select the appropriate clock ratios. Changes to these bits should only be done while the
PDN bit is set. Depending on whether the CS4270 is in Master or Slave Mode, different MCLK/LRCK and
SCLK/LRCK ratios may be used. These ratios as well as the Serial Control Port Register Bits are shown
in Table 7, Table 10 on page 33, and Section 8.3 on page 33. ‘0’ = DGND, ‘1’ = VLC.
Master Mode
Speed Mode
Single-Speed
Double-Speed
Quad-Speed
MCLK/LRCK
SCLK/LRCK
LRCK MCLK_FREQ2 MCLK_FREQ1 MCLK_FREQ0
256
64
Fs
0
0
0
384
64
Fs
0
0
1
512
64
Fs
0
1
0
768
64
Fs
0
1
1
1,024
64
Fs
1
0
0
128
64
Fs
0
0
0
192
64
Fs
0
0
1
256
64
Fs
0
1
0
384
64
Fs
0
1
1
512
64
Fs
1
0
0
64
64
Fs
0
0
0
96
64
Fs
0
0
1
128
64
Fs
0
1
0
192
64
Fs
0
1
1
256
64
Fs
1
0
0
Table 7. Clock Ratios - Serial Control Port Mode
22
DS686F1
CS4270
Slave Mode
Speed Mode
Single-Speed
Double-Speed
Quad-Speed
MCLK/LRCK
SCLK/LRCK
256
32, 48, 64, 128
LRCK MCLK_FREQ2 MCLK_FREQ1 MCLK_FREQ0
384
32, 48, 64, 96, 128
Fs
0
0
1
512
32, 48, 64, 128
Fs
0
1
0
Fs
0
0
0
768
32, 48, 64, 96, 128
Fs
0
1
1
1,024
32, 48, 64, 96, 128
Fs
1
0
0
128
32, 48, 64
Fs
0
0
0
192
32, 48, 64
Fs
0
0
1
256
32, 48, 64
Fs
0
1
0
384
32, 48, 64
Fs
0
1
1
512
32, 48, 64
Fs
1
0
0
64
32, 48, 64
Fs
0
0
0
96
32, 48, 64
Fs
0
0
1
128
32, 48, 64
Fs
0
1
0
192
32, 48, 64
Fs
0
1
1
256
32, 48, 64
Fs
1
0
0
Table 7. Clock Ratios - Serial Control Port Mode (Continued)
5.2.5
Internal Digital Loopback
In Serial Control Port Mode, the CS4270 supports an internal digital loopback mode in which the output
of the ADC is routed to the input of the DAC. This mode may be activated by setting the DIG_LOOPBK
bit in the ADC and DAC Control register (04h).
When this bit is set, the CS4270 ignores the status of the DAC_DIF(4:3) bits in register 04h. Any changes
made to the DAC_DIF(4:3) bits while the DIG_LOOPBK bit is set will have no impact on operation until
the DIG_LOOPBK bit is released, at which time the Digital Interface Format of the DAC will operate according to the format selected in the DAC_DIF(4:3) bits. While the DIG_LOOPBK bit is set, data will be
present on the SDOUT pin in the format selected in the ADC_DIF(0) bit in register 04h.
5.2.6
Auto-Mute
The Auto-Mute function is controlled by the status of the Auto Mute bit in the Mute register. When set, the
DAC output will mute following the reception of 8192 consecutive audio samples of static 0 or -1. A single
sample of non-static data will release the mute. Detection and muting are done independently for each
channel. The common mode on the output will be retained and the Mute Control pin for that channel will
become active during the mute period. The muting function is affected, similar to volume control changes,
by the Soft and Zero Cross bits in the Transition and Control register. The Auto Mute bit is set by default.
5.2.7
DC Offset Calibration Using the High-Pass Filter
At the system level, the input circuitry driving the CS4270 may generate a small DC offset level into the
A/D converter which could result in possibly yielding "clicks" when switching between devices in a multichannel system. The CS4270 includes one high-pass filter per channel (see “ADC High Pass Filter Freeze
for CH A (Bit 7)” on page 34 and “ADC High Pass Filter Freeze for CH A (Bit 7)” on page 34) to alleviate
this system problem.
Running the CS4270 with the high-pass filter enabled, then freezing the stored DC offset value eliminates
offsets anywhere in the signal path between the calibration point and the CS4270.
DS686F1
23
CS4270
5.2.8
Oversampling Modes
The CS4270 operates in one of three oversampling modes based on the input sample rate. Mode selection is determined by the FM bits in the Mode Control Register (03h). Single-Speed Mode supports input
sample rates from 4 to 54 kHz and uses a 128x oversampling ratio. Double-Speed Mode supports input
sample rates from 50 to 108 kHz and uses an oversampling ratio of 64x. Quad-Speed Mode supports input sample rates from 100 to 216 kHz and uses an oversampling ratio of 32x. See Table 7 on page 22.
5.3
Popguard Transient Control
The CS4270 uses a novel technique to minimize the effects of output transients during power-up and powerdown. This technology, when used with external DC-blocking capacitors in series with the audio outputs,
minimizes the audio transients commonly produced by single-ended single-supply converters. The Popguard Transient Control is activated inside the DAC when RST is toggled and requires no other external
control, aside from choosing the appropriate DC-blocking capacitor. See Section 8.3.3 for information about
configuration.
5.3.1
Power-Up
When the device is initially powered-up, the audio outputs, AOUTA and AOUTB, are clamped to
AGND.Following a delay of 1,045 sample periods, each output begins to ramp toward the quiescent voltage. Approximately 0.4 seconds later, the outputs reach VQ and audio output begins.This gradual voltage
ramping allows time for the external DC-blocking capacitors to charge to the quiescent voltage, minimizing
audible power-up transients.
5.3.2
Power-Down
To prevent audible transients at power-down, the device must first enter its power-down state. When this
occurs, audio output ceases and the internal output buffers are disconnected from AOUTA and AOUTB.
In their place, a soft-start current sink is substituted which allows the DC-blocking capacitors to slowly discharge. Once this charge is dissipated, the power to the device may be turned off and the system is ready
for the next power-on.
5.3.3
Discharge Time
To prevent an audio transient at the next power-on, the DC-blocking capacitors must fully discharge before turning on the power or exiting the power-down state. If full discharge does not occur, a transient will
occur when the audio outputs are initially clamped to AGND. The time that the device must remain in the
power-down state is related to the value of the DC-blocking capacitance and the output load. For example,
with a 3.3 F capacitor, the minimum power-down time will be approximately 0.4 seconds.
5.4
De-Emphasis Filter (Single-Speed Mode Only)
The CS4270 includes a digital de-emphasis filter. Figure 14 shows the de-emphasis curve for Fs equal to
44.1 kHz. The frequency response of the de-emphasis curve will scale proportionally with changes in
sample rate, Fs. Please see Section 5.1.7 for the desired de-emphasis control for Stand-Alone Mode and
Section 5.2 for Serial Control Port Mode.
The de-emphasis feature is included to accommodate audio recordings that use 50/15 s pre-emphasis
equalization as a means of noise reduction.
24
DS686F1
CS4270
Gain
dB
T1=50 µs
0dB
T2 = 15 µs
-10dB
F1
3.183 kHz
F2
Frequency
10.61 kHz
Figure 14. De-Emphasis Curve
5.5
Analog Connections
The analog modulator samples the input at 6.144 MHz for Fs = 48, 96, and 128 kHz and scales proportionally for all other sampling speeds.The digital filter rejects signals within the stopband of the filter. However, there is no rejection for input signals that are multiples of the input sampling frequency (e.g.,
n  6.144 MHz), where n = 0, 1, 2, ... . Figure 15 shows the recommended topology of the analog input
network. The capacitor values are chosen not only provide the appropriate filtering of noise at the modulator sampling frequency, but to act as a charge source for the internal sampling circuits. The use of capacitors with a large voltage coefficient (such as general-purpose ceramics) can degrade signal linearity.
5.5.1
Input Component Values
Table 8 shows the three parameters (source impedance, attenuation, and input impedance) that determine the values of resistors R1 and R2, as seen in Figure 15, and shows the design equations used to
determine these values.
Parameter
Equation
Source Impedance: The impedance as seen from the ADC looking back into the signal
network. The ADC achieves optimal THD+N performance when source impedance less
than or equal to 1.0 k. See Figure 16 and 17.
-----------------------R1  R2 R1 + R2
Attenuation: The required attenuation factor depends on the magnitude of the input signal. For VA = 5 V, the full-scale input voltage equals 0.56*VA (1 Vrms). See ADC Analog
Characteristics on page 11. The user should select values for R1 and R2 such that the
magnitude of the incoming signal multiplied by the attenuation factor is less than or equal
to the full-scale input voltage of the device.
Input Impedance: Input impedance is the impedance from the signal source to the ADC
analog input pins. Table 8 shows the input parameters and the associated design equations.
 R2  ----------------------- R1 + R2 
 R1 + R2 
Table 8. Analog Input Design Parameters
Figure 15 illustrates an example configuration using two 2-kresistors in place of R1 and R2. This circuit
will attenuate a typical line level voltage, 2 Vrms, to the full-scale input of the ADC, 0.56*VA (1 Vrms) when
VA = 5 V.
DS686F1
25
CS4270
2 k
(R1)
Analog
Input
10 µF
+
AINx
2 k
(R2)
220 pF
CS4270
Figure 15. CS4270 Example Analog Input Network
-60
-65
-70
ADC THD+N @ 1kHz
-75
-80
-85
-90
-95
-100
-105
-110
1
10
ADC Source Impedance (kOhms)
(k )
Figure 16. A/D THD+N Performance vs. Input Source Impedance
106
104
ADC Dynamic Range
102
100
98
96
94
92
90
88
1
10
100
(k )
ADC Source Impedance (kOhms)
Figure 17. A/D Dynamic Range vs. Input Source Impedance
26
DS686F1
CS4270
5.5.2
Output Connections
The analog output filter present in the CS4270 is a switched-capacitor low pass filter. Its response, combined with that of the digital interpolator, is given in Figures 23 - 46. The recommended external analog
circuitry is shown in Figure 18.
470 
3.3 µF
Analog Output
AOUTx
+
C
R
ext
10 k
CS4270
C =
Rext
+ 470
4Fs ( Rext 470 )
Figure 18. CS4270 Recommended Analog Output Filter
5.6
Mute Control
The Mute Control pins become active during power-up initialization, reset, muting, when the MCLK to LRCK
ratio is incorrect, and during power-down. The MUTE pins are intended to be used as control for an external
mute circuit in order to add device mute capability.
The CS4270 also features Auto-Mute, which is enabled by default. The Auto-Mute function causes the
MUTE pin corresponding to an individual channel to activate following the reception of 8192 consecutive
static-level audio samples on the respective channel. A single transition of data on the channel will cause
the corresponding MUTE pin to deactivate.
Use of the Mute Control function is not mandatory but recommended for designs requiring the absolute minimum in extraneous clicks and pops. Also, use of the Mute Control function can enable the system designer
to achieve idle channel noise/signal-to-noise ratios which are only limited by the external mute circuit. The
MUTE pins are active-low. See Figure 19 for a suggested active-low mute circuit.
+V
AC
Couple
AOUTx
560 
LPF
Audio
Out
47 k
-V
CS4270
+VA
MMUN2111LT1
MUTEx
2 k
10 k
-V
Figure 19. Suggested Active-Low Mute Circuit
DS686F1
27
CS4270
5.7
Synchronization of Multiple Devices
In systems where multiple ADCs are required, care must be taken to achieve simultaneous sampling. To
ensure synchronous sampling, the MCLK and LRCK must be the same for all of the CS4270s in the system.
If only one MCLK source is needed, one solution is to place one CS4270 in Master Mode, and slave all of
the other CS4270s to the one master. If multiple MCLK sources are needed, a possible solution would be
to supply all clocks from the same external source and time the CS4270 reset with the inactive edge of
MCLK. This will ensure that all converters begin sampling on the same clock edge.
5.8
Grounding and Power Supply Decoupling
As with any high resolution converter, the CS4270 requires careful attention to power supply and grounding
arrangements if its potential performance is to be realized. Figure 1 on page 7 shows the recommended
power arrangements, with VA, VD and VLC connected to clean supplies. VD, which powers the digital filter,
may be run from the system digital supply or may be powered from the analog supply via a resistor. In the
latter case, no additional devices should be powered from VD. See Figure 1 on page 7 for an example. Power supply decoupling capacitors should be as near to the CS4270 as possible, with the low value ceramic
capacitor being the nearest. All signals, especially clocks, should be kept away from the FILT+ and VQ pins
in order to avoid unwanted coupling into the modulators. The FILT+ and VQ decoupling capacitors, particularly the 0.1 µF, must be positioned to minimize the electrical path to AGND. The CDB4270 evaluation
board demonstrates the optimum layout and power supply arrangements. To minimize digital noise, connect
the CS4270 digital outputs only to CMOS inputs.
6. SOFTWARE MODE
6.1
Software Mode - I²C Control Port
Software Mode is used to access the registers, allowing the CS4270 to be configured for the desired operational modes and formats. The operation in Software Mode may be completely asynchronous with respect
to the audio sample rates. However, to avoid potential interference problems, the I²C pins should remain
static if no operation is required. Software Mode supports the I²C interface, with the CS4270 acting as a
slave device.
SDA is a bidirectional data line. Data is clocked into and out of the part by the clock, SCL. Pin AD0 forms
the least significant bit of the chip address and should be connected through a resistor to VL or GND as
desired. The state of the pin is sensed while the CS4270 is being reset.
The signal timings for a read and write cycle are shown in Figure 20 and Figure 21. A Start condition is defined as a falling transition of SDA while the clock is high. A Stop condition is a rising transition while the
clock is high. All other transitions of SDA occur while the clock is low. The first byte sent to the CS4270 after
a Start condition consists of a 7-bit chip address field and a R/W bit (high for a read, low for a write). The
upper 5 bits of the 7-bit address field are fixed at 10011. To communicate with a CS4270, the chip address
field, which is the first byte sent to the CS4270, should match 10011 followed by the settings of AD0. The
eighth bit of the address is the R/W bit. If the operation is a write, the next byte is the Memory Address Pointer (MAP) which selects the register to be read or written. If the operation is a read, the contents of the register pointed to by the MAP will be output. Setting the auto increment bit in MAP allows successive reads or
writes of consecutive registers. Each byte is separated by an acknowledge bit. The ACK bit is output from
the CS4270 after each input byte is read, and is input to the CS4270 from the microcontroller after each
transmitted byte.
28
DS686F1
CS4270
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18
24 25 26 27 28
19
SCL
CHIP ADDRESS (WRITE)
1
SDA
0
0
1
MAP BYTE
1 AD1 AD0 0
6
INCR
5
4
3
2
1
0
ACK
7
6
1
ACK
DATA +n
DATA +1
DATA
0
7
6
1
0
7
6
1
ACK
0
ACK
STOP
START
Figure 20. Software Mode Timing, I²C Write
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16
17 18
19
20 21 22 23 24 25 26 27 28
SCL
CHIP ADDRESS (WRITE)
SDA
1
0
0
1
STOP
MAP BYTE
0 AD1 AD0 0
INCR
6
5
4
3
ACK
START
2
1
CHIP ADDRESS (READ)
1
0
0
0
1
DATA
0 AD1 AD0 1
ACK
START
7
ACK
DATA +1
0
7
ACK
0
DATA + n
7
0
NO
ACK
STOP
Figure 21. Software Mode Timing, I²C Read
Since the read operation can not set the MAP, an aborted write operation is used as a preamble. As shown
in Figure 21, the write operation is aborted after the acknowledge for the MAP byte by sending a stop condition. The following pseudocode illustrates an aborted write operation followed by a read operation.
Send start condition.
Send 10011xx0 (chip address & write operation).
Receive acknowledge bit.
Send MAP byte, auto increment off.
Receive acknowledge bit.
Send stop condition, aborting write.
Send start condition.
Send 10011xx1(chip address & read operation).
Receive acknowledge bit.
Receive byte, contents of selected register.
Send acknowledge bit.
Send stop condition.
Setting the auto increment bit in the MAP allows successive reads or writes of consecutive registers. Each
byte is separated by an acknowledge bit.
6.2
Software Mode - SPI Control Port
In SPI Mode, data is clocked into the serial control data line, CDIN, by the serial clock, CCLK (see Figure 22
for the clock to data relationship). There are no AD0 or AD1 pins. Pin CS is the chip select signal and is
used to control SPI writes to the registers. When the device detects a high-to-low transition on the AD0/CS
pin after power-up, SPI Mode will be selected. All signals are inputs and data is clocked in on the rising edge
of CCLK.
6.2.1
SPI Write
To write to the device, use the following procedure while adhering to the Software Mode switching specifications in “Switching Characteristics - Software Mode - SPI Format” section on page 18.
DS686F1
29
CS4270
1. Bring CS low.
2. The address byte on the CDIN pin must then be 10011110 (R/W = 0).
3. Write to the memory address pointer, MAP. This byte points to the register to be written.
4. Write the desired data to the register pointed to by the MAP.
5. If the INCR bit (see Section 6.2.3.1) is set to 1, repeat the previous step until all the desired registers
are written, then bring CS high.
6. If the INCR bit is set to 0 and further SPI writes to other registers are desired, it is necessary to bring
CS high, and follow the procedure detailed from step 1. If no further writes to other registers are
desired, bring CS high
6.2.2
SPI Read
To read from the device, use the following procedure while adhering to the values specified in “Switching
Characteristics - Software Mode - SPI Format” section on page 18.
1.
Bring CS low.
2. The address byte on the CDIN pin must then be 10011111 (R/W = 1).
3. CDOUT pin will then output the data from the register pointed to by the MAP, which is set during the
SPI write operation.
4. If the INCR bit (see Section 6.2.3.1) is set to 1, keep CS low and continue providing clocks on CCLK
to read from multiple consecutive registers. Bring CS high when reading is complete.
5. If the INCR bit is set to 0 and further SPI reads from other registers are desired, it is necessary to bring
CS high, and follow the procedure detailed from step 1. If no further reads from other registers are
desired, bring CS high.
CS
CCLK
C H IP
ADDRESS
CDIN
1001111
MAP
MSB
R/W
b y te 1
CDOUT
C H IP
ADDRESS
DATA
LSB
1001111
R/W
b y te n
High Impedance
MSB
LSB MSB
LSB
MAP = Memory Address Pointer, 8 bits, MSB first
Figure 22. Software Mode Timing, SPI Mode
30
DS686F1
CS4270
6.2.3
Memory Address Pointer (MAP)
The MAP byte comes after the address byte and selects the register to be read or written. Refer to
Figures 20 and 21 on page 29, and Figure 22 on page 30.
6.2.3.1
Map Increment (INCR)
The device has MAP auto increment capability enabled by the INCR bit (the MSB) of the MAP. If INCR is
set to 0, MAP will stay constant for successive I²C writes or reads and SPI writes. If INCR is set to 1, MAP
will auto increment after each byte is written, allowing block reads or writes of successive registers.
7. REGISTER QUICK REFERENCE
This table shows the register and register bit names and their associated default values.
Addr
Function
01h Device ID
p 32
02h Power Control
p 32
03h Mode Control
p 33
04h ADC and DAC
Control
p 34
05h Transition
Control
p 35
06h Mute Control
p 36
07h DAC Channel A
Volume Control
p 36
08h DAC Channel B
Volume Control
p 37
DS686F1
7
6
5
4
3
2
1
0
ID3
ID2
ID1
ID0
REV3
REV2
REV1
REV0
1
0
0
0
0
1
Freeze
0
Reserved PDN_ADC Reserved
0
0
Reserved Reserved
0
0
0
0
MCLK_
FREQ1
MCLK_
FREQ0
POPG
0
0
0
Reserved
ADC_DIF0
0
0
Reserved
Reserved
FM1
FM0
0
0
1
1
0
ADC_HPF_ ADC_HPF_
DIG_
DAC_DIF1 DAC_DIF0 Reserved
FRZ_A
FRZ_B
LOOPBK
0
0
1
PDN
0
MCLK_
FREQ2
0
0
PDN_DAC
0
0
0
DAC_SNGL_
ADC_INV_ ADC_INV_ DAC_INV_
DAC_SOFT DAC_ZC
DAC_INV_A
VOL
B
A
B
0
Reserved
1
1
Reserved
AUTO_
MUTE
0
0
MUTE_
MUTE_
ADC_CHB ADC_CH A
0
MUTE_
POL
0
DE_EMPH
0
MUTE_DAC_ MUTE_DAC_
CHB
CHA
0
0
1
0
0
0
0
0
DACA_
VOL7
DACA_
VOL6
DACA_
VOL5
DACA_
VOL4
DACA_
VOL3
DACA_
VOL2
DACA_
VOL1
DACA_
VOL0
0
0
0
0
0
0
0
0
DACB_
VOL7
DACB_
VOL6
DACB_
VOL5
DACB_
VOL4
DACB_
VOL3
DACB_
VOL2
DACB_
VOL1
DACB_
VOL0
0
0
0
0
0
0
0
0
31
CS4270
8. REGISTER DESCRIPTION
** All registers are read/write in I²C Mode and SPI Mode, unless otherwise noted**
8.1
Device ID - Address 01h
7
ID3
6
ID2
5
ID1
4
ID0
3
REV3
2
REV2
1
REV1
0
REV0
Function:
This register is read only. Bits 7 through 4 are the device ID, which is 1100b (0Ch) and the remaining bits
REV[3:0] are for the device revision.
8.2
Power Control - Address 02h
7
Freeze
8.2.1
6
Reserved
5
PDN_ADC
4
Reserved
3
Reserved
2
Reserved
1
PDN_DAC
0
PDN
Freeze (Bit 7)
Function:
This function allows changes to registers 05h–08h without the changes taking effect until the Freeze bit
is cleared. To make multiple changes to these bits take effect simultaneously, set the Freeze bit, make all
changes, then clear the Freeze bit.
8.2.2
PDN_ADC (Bit 5)
Function:
The ADC portion of the device will enter a low-power state whenever this bit is set.
8.2.3
PDN_DAC (Bit 1)
Function:
The DAC portion of the device enters a low-power state when this bit is set.
8.2.4
Power Down (Bit 0)
Function:
The device enters a low-power state when this bit is set. The contents of all registers are retained when
the device is in power-down.
32
DS686F1
CS4270
8.3
Mode Control - Address 03h
7
Reserved
8.3.1
6
Reserved
5
FM1
4
FM0
3
2
1
MCLK_FREQ2 MCLK_FREQ1 MCLK_FREQ0
0
POPG
ADC Functional Mode & Master/Slave Mode (Bits 5:4)
Function:
In Master Mode, the user must configure the CS4270 Speed Mode with these bits. In Slave Mode, the
CS4270 auto-detects the speed mode.
FM1
Mode
FM0
0
0
Single-Speed Master Mode: 4 to 54 kHz sample rates
0
1
Double-Speed Master Mode: 50 to 108 kHz sample rates
1
0
Quad-Speed Master Mode: 100 to 216 kHz sample rates
1
1
Slave Mode (default)
Table 9. Functional Mode Selection
8.3.2
Ratio Select (Bits 3:1)
Function:
These bits are used to select the clocking ratios. The PDN bit should be set before, and cleared after, any
changes to these bits.
MCLK_FREQ2
MCLK_FREQ1
MCLK_FREQ0
Mode
0
0
0
Divide by 1 (default)
0
0
1
Divide by 1.5
0
1
0
Divide by 2
0
1
1
Divide by 3
1
0
0
Divide by 4
Table 10. MCLK Divider Configuration
8.3.3
Popguard Transient Control (Bit 0)
Function:
When set, the Popguard Transient Control allows the quiescent voltage to slowly ramp to and from AGND
to the quiescent voltage during power-on or power-off when this function is set. When cleared (default),
this function is disabled. See Section 5.3 for additional details about Popguard.
DS686F1
33
CS4270
8.4
ADC and DAC Control - Address 04h
7
ADC_HPF_
FRZ_A
8.4.1
6
ADC_HPF_
FRZ_B
5
DIG_
LOOPBK
4
3
2
1
0
DAC_DIF1
DAC_DIF0
Reserved
Reserved
ADC_DIF0
ADC High Pass Filter Freeze for CH A (Bit 7)
Function:
When this bit is set, the internal high-pass filter DC offset value for channel A are frozen.This value is continuously subtracted from the conversion result. To recalibrate ADC channel A and obtain a new or continuous value for the system DC offset, clear this bit. See “DC Offset Calibration Using the High-Pass
Filter” on page 23.
8.4.2
ADC High Pass Filter Freeze for CH B (Bit 6)
Function:
When this bit is set, the internal high-pass filter for channel B are frozen.The current DC offset value will
be static and continuously subtracted from the conversion. To recalibrate ADC channel A and obtain a
new or continuous value for the system DC offset, clear this bit. See “DC Offset Calibration Using the
High-Pass Filter” on page 23.
8.4.3
Digital Loopback (Bit 5)
Function:
When this bit is set, an internal digital loopback from the ADC to the DAC will be enabled. See Section
5.2.5 “Internal Digital Loopback” on page 23.
8.4.4
DAC Digital Interface Format (Bits 4:3)
Function:
The DAC_Digital_Interface_Format and the options are detailed in Table 11 and Figures 9–11.
DAC_DIF1 DAC_DIF0
Description
0
0
Left Justified, up to 24-bit data (default)
0
1
I²S, up to 24-bit data
1
1
Right-Justified, 16-bit Data
1
0
Right-Justified, 24-bit Data
Format
0
1
2
3
Figure
9
10
11
11
Table 11. DAC Digital Interface Formats
8.4.5
ADC Digital Interface Format (Bit 0)
Function:
The required relationship between LRCK, SCLK, and SDOUT for the ADC is defined by the ADC Digital
Interface Format. The options are detailed in Table 12 and may be seen in Figures 9 and 10.
ADC_DIF
Description
Format
Figure
0
Left Justified, up to 24-bit data (default)
0
9
1
I²S, up to 24-bit data
1
10
Table 12. ADC Digital Interface Formats
34
DS686F1
CS4270
8.5
Transition Control - Address 05h
7
DAC_SNGL_
VOL
8.5.1
6
5
DAC_SOFT
DAC_ZC
4
ADC_INV_
CHB
3
ADC_INV_
CHA
2
DAC_INV_
CHB
1
DAC_INV_
CHA
0
DE_EMPH
DAC Single Volume (Bit 7)
Function:
The AOUTA and AOUTB volume levels are independently controlled by the DAC Channel A & B Volume
Control Registers when this bit is cleared.
The volumes on AOUTA and AOUTB are locked together and determined by the DAC Channel A Volume
Control Register (07h) when this bit is set.
8.5.2
Soft Ramp and Zero Cross Enable (Bits 6:5)
Function:
Soft Ramp Enable
Soft Ramp allows level changes, both muting and attenuation, to be implemented by incrementally ramping, in 1/8 dB steps, from the current level to the new level at a rate of 1 dB per 8 left/right clock periods.
See Table 13 on page 35.
Zero Cross Enable
Zero Cross Enable dictates that signal level changes, either by attenuation changes or muting, will occur
on a signal zero crossing to minimize audible artifacts. The requested level change will occur after a timeout period between 512 and 1,024 sample periods (10.7 ms to 21.3 ms at 48 kHz sample rate) if the signal
does not encounter a zero crossing. The zero cross function is independently monitored and implemented
for each channel.
Soft Ramp and Zero Cross Enable
Soft Ramp and Zero Cross Enable dictate that signal level changes, either by attenuation changes or muting, will occur in 1/8 dB steps and be implemented on a signal zero crossing. The 1/8 dB level change will
occur after a time-out period between 512 and 1,024 sample periods (10.7 ms to 21.3 ms at 48 kHz sample rate) if the signal does not encounter a zero crossing. The zero cross function is independently monitored and implemented for each channel. See Table 10 on page 33.
DAC_SOFT DAC_ZC
Mode
0
0
Changes take effect immediately
0
1
Zero Cross enabled
1
0
Soft Ramp enabled
1
1
Soft Ramp and Zero Cross enabled (default)
Table 13. Soft Cross or Zero Cross Mode Selection
8.5.3
Invert Signal Polarity (Bits 4:1)
Function:
When set, this bit activates an inversion of the signal polarity for the appropriate channel. This is useful if
a board layout error has occurred or in other situations where a 180 phase shift is desirable.
DS686F1
35
CS4270
8.5.4
De-Emphasis Control (Bit 0)
Function:
When this bit is set, the standard 50/15 s digital de-emphasis filter is applied on the DAC output. Figure
14 on page 25 shows the filter response. NOTE: De-emphasis is available only in Single-Speed Mode.
When this bit is cleared, no de-emphasis is applied to the DAC outputs.
8.6
Mute Control - Address 06h
7
6
Reserved
Reserved
8.6.1
5
4
3
MUTE_ADC_ MUTE_ADC_
AUTO_MUTE
CHB
CHA
2
MUTE_POL
1
0
MUTE_DAC_ MUTE_DAC_
CHB
CHA
Auto-Mute (Bit 5)
Function:
When set, enables the Auto-Mute function. Section 5.2.6 “Auto-Mute” on page 23.
8.6.2
ADC Channel A & B Mute (Bits 4:3)
Function:
When this bit is set, the output of the ADC for the selected channel will be muted.
8.6.3
Mute Polarity (Bit 2)
Function:
The MUTEA and MUTEB pins (pins 24 and 21) are active low by default. When this bit is set, these pins
are active high.
8.6.4
DAC Channel A & B Mute (Bits 1:0)
Function:
When this bit is set, the output of the DAC for the selected channel will be muted.
8.7
DAC Channel A Volume Control - Address 07h
7
DACA_
VOL7
6
DACA_
VOL6
5
DACA_
VOL5
4
DACA_
VOL4
3
DACA_
VOL3
2
DACA_
VOL2
1
DACA_
VOL1
0
DACA_
VOL0
Function:
See Section 8.8 DAC Channel B Volume Control - Address 08h.
36
DS686F1
CS4270
8.8
DAC Channel B Volume Control - Address 08h
7
DACB
VOL7
6
DACB
VOL6
5
DACB
VOL5
4
DACB
VOL4
3
DACB
VOL3
2
DACB
VOL2
1
DACB
VOL1
0
DACB
VOL0
Function:
The digital volume control allows the user to attenuate the signal in 0.5 dB increments from 0 to -127 dB.
VOL0 activates a 0.5 dB attenuation when set, and no attenuation when cleared. VOL[7:0] activates attenuation equal to their decimal value (in dB). Example volume settings are decoded as shown in
Table 14. The volume changes are implemented as dictated by the DAC_SOFT and DAC_ZC bits in the
Transition Control register (see Section 8.5.2).
Binary Code
Volume Setting
00000000
0 dB
00000001
-0.5 dB
00101000
-20 dB
00101001
-20.5 dB
11111110
-127 dB
11111111
-127.5 dB
Table 14. Digital Volume Control
DS686F1
37
CS4270
9. FILTER PLOTS
Figure 23. DAC Single-Speed Stopband Rejection
Figure 24. DAC Single-Speed Transition Band
0
-1
0.05
-2
0
-3
-0.05
Amplitude dB
Amplitude dB
-4
-5
-6
-0. 1
-0.15
-7
-0. 2
-8
-0.25
-9
-10
0.45
38
0.46
0.47
0.48
0.49
0.5
0.51
Frequency (normalized to Fs)
0.52
0.53
0.54
0.5 5
0
0.05
0.1
0.15
0.2
0.25
0.3
Frequency (normalized to Fs)
0.35
0.4
0.45
0.5
Figure 25. DAC Single-Speed Transition Band (detail)
Figure 26. DAC Single-Speed Passband Ripple
Figure 27. DAC Double-Speed Stopband Rejection
Figure 28. DAC Double-Speed Transition Band
DS686F1
CS4270
1
0.8
0
0.7
-1
0.6
-2
0.5
Amplitude dB
Amplitude dB
-3
-4
-5
0.4
0.3
0.2
-6
0.1
-7
0
-8
-0. 1
-9
-0. 2
- 10
0.45
0.46
0.47
0.48
0.49
0.5
0.51
Frequency (normalized to Fs)
0.52
0.53
0.54
0.55
Figure 29. DAC Double-Speed Transition Band (detail)
0
0.05
0.1
0.15
0.2
0.25
0.3
Frequency (normalized to Fs)
0.35
0.4
0.45
0.5
Figure 30. DAC Double-Speed Passband Ripple
0
0
-10
-10
-20
-30
-20
Amplitude (dB)
Amplitude (dB)
-40
-50
-60
-30
-40
-70
-50
-80
-60
-90
-100
0
0.1
0.2
0.3
0.4
0.5
0.6
Frequency(normalized to Fs)
0.7
0.8
0.9
1
0.35
Figure 31. DAC Quad-Speed Stopband Rejection
0.4
0.45
0.5
0.55
0.6
Frequency(normalized to Fs)
0.65
0.7
0.75
Figure 32. DAC Quad-Speed Transition Band
0
0
-5
-10
-15
Amplitude dB
Amplitude (dB)
-0. 5
-20
-25
-30
-1
-35
-40
-45
-50
0.4
0.45
0.5
0.55
0.6
Frequency(normalized to Fs)
0.65
0.7
Figure 33. DAC Quad-Speed Transition Band (detail)
DS686F1
-1. 5
0
0.05
0.1
0.15
0.2
0.25
0.3
Frequency (normalized to Fs)
0.35
0.4
0.45
0.5
Figure 34. DAC Quad-Speed Passband Ripple
39
0
0
-10
-20
-10
-20
-30
-30
-40
-40
Amplitude (dB)
Amplitude (dB)
CS4270
-50
-60
-70
-80
-90
-100
-50
-60
-70
-80
-90
-100
-110
-110
-120
-130
-120
-130
-140
0.40 0.42 0.44
-140
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0
0.10
-1
0.08
-2
0.06
-3
0.04
-4
-5
-6
0.56
0.58
0.60
-7
0.00
-0.02
-0.04
-8
-0.06
-9
-0.08
-0.10
0.46 0.47
0.48
0.49
0.5
0.51
0.52
0.53
0.54
0
0.55
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
Frequency (norm alized to Fs)
Figure 37. ADC Single-Speed Transition Band (detail)
Figure 38. ADC Single-Speed Passband Ripple
0
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
-140
-10
-20
-30
Amplitude (dB)
Amplitude (dB)
0.54
0.02
Frequency (norm alized to Fs)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Frequency (norm alized to Fs)
Figure 39. ADC Double-Speed Stopband Rejection
40
0.52
Figure 36. ADC Single-Speed Stopband (detail)
Amplitude (dB)
Amplitude (dB)
Figure 35. ADC Single-Speed Stopband Rejection
-10
0.45
0.46 0.48 0.50
Frequency (norm alized to Fs)
Frequency (norm alized to Fs)
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
-140
0.40 0.42 0.44
0.46 0.48 0.50
0.52
0.54
0.56
0.58
0.60
Frequency (norm alized to Fs)
Figure 40. ADC Double-Speed Stopband (detail)
DS686F1
0
0.10
-1
0.08
-2
0.06
-3
0.04
Amplitude (dB)
Amplitude (dB)
CS4270
-4
-5
-6
-7
0.02
0.00
-0.02
-0.04
-8
-0.06
-9
-0.08
-10
0.46
0.47
0.48
0.49
0.50
0.51
-0.10
0.00 0.05
0.52
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
-140
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.15
0.20 0.25 0.30 0.35 0.40 0.45 0.50
Figure 42. ADC Double-Speed Passband Ripple
Amplitude (dB)
Amplitude (dB)
Figure 41. ADC Double-Speed Transition Band (detail)
0.0
0.10
Frequency (norm alized to Fs)
Frequency (norm alized to Fs)
0.8
0.9
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
-140
0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85
1.0
Frequency (norm alized to Fs)
Frequency (norm alized to Fs)
Figure 43. ADC Quad-Speed Stopband Rejection
Figure 44. ADC Quad-Speed Stopband (detail)
0.10
-2
0.08
-3
0.06
-4
0.04
Amplitude (dB)
Amplitude (dB)
0
-1
-5
-6
-7
-8
-9
-10
0.10
0.00
-0.02
-0.04
-0.06
-0.08
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
Frequency (norm alized to Fs)
Figure 45. ADC Quad-Speed Transition Band (detail)
DS686F1
0.02
-0.10
0.00 0.03 0.05 0.08 0.10 0.13 0.15 0.18 0.20 0.23 0.25 0.28
Frequency (norm alized to Fs)
Figure 46. ADC Quad-Speed Passband Ripple
41
CS4270
10.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 bandwidth
(typically 10 Hz to 20 kHz), including distortion components. Expressed in decibels. For ADCs, measured at -1 and
-20 dBFS as suggested in AES17-1991 Annex A. For DACs, measured at 0 dB relative to full scale.
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.
42
DS686F1
CS4270
11.PACKAGE DIMENSIONS
24L TSSOP (4.4 mm BODY) PACKAGE DRAWING
N
D
E11
A2
E
A

b2
e
A1
SIDE VIEW
L
END VIEW
SEATING
PLANE
1 2 3
TOP VIEW
DIM
A
A1
A2
b
D
E
E1
e
L
µ
INCHES
MILLIMETERS
MIN
NOM
MAX
MIN
NOM
--0.47
--0.00197
0.00394
0.00591
0.05
0.10
0.03150
0.0394
0.04137
0.80
1.00
0.00748
0.00965
0.01182
0.19
0.245
0.30338 BSC 0.30732 BSC 0.31126 BSC
7.70 BSC
7.80 BSC
0.24822
0.25216
0.25610
6.30
6.40
0.16942
0.17336
0.17730
4.30
4.40
-0.026 BSC
--0.65 BSC
0.01970
0.02364
0.02955
0.50
0.60
0°
4°
8°
0°
4°
JEDEC #: MO-153
Controlling Dimension is Millimeters.
NOTE
MAX
1.20
0.15
1.05
0.30
7.90 BSC
6.50
4.50
-0.75
8°
2,3
1
1
1. “D” and “E1” are reference datums and do not include 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.
THERMAL CHARACTERISTICS
Parameters
Allowable Junction Temperature
Junction to Ambient Thermal Impedance (Note 4)
(Multi-layer PCB) TSSOP
(Single-layer PCB) TSSOP
Symbol
JA-M
JA-S
Min
Typ
Max
Units
-
-
135
C
-
70
105
-
C/W
C/W
4. JA is specified according to JEDEC specifications for multi-layer PCBs.
DS686F1
43
CS4270
12.ORDERING INFORMATION
Product
CS4270
Description
Package
24-Bit 192 kHz Stereo Audio CODEC 24-TSSOP
CDB4270
CS4270 Evaluation Board
-
Pb-Free
YES
-
Temp Range
Container
Order #
Rail
CS4270-CZZ
-10° to +70° C
Tape & Reel CS4270-CZZR
CDB4270
13.REVISION HISTORY
Release
Changes
–
–
–
–
–
–
F1
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
44
Deleted automotive grade content and references to grade throughout.
Formatting changes throughout.
Updated several “Pin Descriptions” on page 4.
Added “Digital I/O Pin Characteristics” on page 6.
Added decoupling cap to VLC on Typical Connection Diagram, Figure 1 on page 7.
Performance specifications updated per measured data in Section 4. “Characteristics and
Specifications” on page 8:
– Min Specified Operating Conditions for “DC Power Supplies:” on page 8.
– Typ and Max DAC Analog Characteristics for “Total Harmonic Distortion + Noise” on page 9.
– Max ADC Analog Characteristics for “Total Harmonic Distortion + Noise” on page 11.
– Typ ADC Analog Characteristics for “Interchannel Isolation” on page 11.
– Typ and Max DC Electrical Characteristics for “Power Supply Current” on page 13.
– Typ and Max DC Electrical Characteristics for “Power Consumption VA = 5 V, VD = VLC=
3.3 V” on page 13.
– Typ DC Electrical Characteristics for “FILT+ Output Impedance” on page 13.
– Min Switching Characteristics - Software Mode - SPI Format for "CCLK High Time" and
“CCLK Low Time” on page 18.
Added “Acknowledge Delay from SCL Falling” on page 17.
Added Transition Time from CCLK to CDOUT Valid (Note 21) and Time from CS rising to CDOUT
High-Z to “Switching Characteristics - Software Mode - SPI Format” on page 18.
Added CDOUT to Figure 13 on page 18.
Added Table 2 on page 19 and associated text in Section 5.1.1 Access to Stand-Alone Mode.
Added Note 22 on page 20.
Updated descriptions of recommended power-up sequences in “Serial Control Port Mode” on
page 21.
Updated “Clock Ratio Selection” on page 22 (added all SCLK/LRCK ratios to the serial control
port mode table).
Updated Section 5.2.7 “DC Offset Calibration Using the High-Pass Filter” on page 23.
Added Section 5.3 “Popguard Transient Control” on page 24.
Updated Section 5.5.1 “Input Component Values” on page 25.
Updated presentation of input source resistance plots (Figure 16 and Figure 17 on page 26).
Added Section 6.2.2 SPI Read on page 30.
Updated bit names in Section 7. “Register Quick Reference” on page 31.
Updated Section 8.3.2 “Ratio Select (Bits 3:1)” on page 33.
Updated Section 8.3.3 “Popguard Transient Control (Bit 0)” on page 33.
Updated Section 8.4.1 and Section 8.4.2 on page 34.
Updated Section 8.5.4 “De-Emphasis Control (Bit 0)” on page 36.
DS686F1
CS4270
Contacting Cirrus Logic Support
For all product questions and inquiries, contact a Cirrus Logic Sales Representative.
To find the one nearest to you, go to www.cirrus.com.
IMPORTANT NOTICE
Cirrus Logic, Inc. and its subsidiaries ("Cirrus") believe that the information contained in this document is accurate and reliable. However, the information is subject
to change without notice and is provided "AS IS" without warranty of any kind (express or implied). Customers are advised to obtain the latest version of relevant
information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale
supplied at the time of order acknowledgment, including those pertaining to warranty, indemnification, and limitation of liability. No responsibility is assumed by Cirrus
for the use of this information, including use of this information as the basis for manufacture or sale of any items, or for infringement of patents or other rights of third
parties. This document is the property of Cirrus and by furnishing this information, Cirrus grants no license, express or implied under any patents, mask work rights,
copyrights, trademarks, trade secrets or other intellectual property rights. Cirrus owns the copyrights associated with the information contained herein and gives consent for copies to be made of the information only for use within your organization with respect to Cirrus integrated circuits or other products of Cirrus. This consent
does not extend to other copying such as copying for general distribution, advertising or promotional purposes, or for creating any work for resale.
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). CIRRUS PRODUCTS ARE NOT DESIGNED, AUTHORIZED OR WARRANTED FOR USE
IN AIRCRAFT SYSTEMS, MILITARY APPLICATIONS, PRODUCTS SURGICALLY IMPLANTED INTO THE BODY, AUTOMOTIVE SAFETY OR SECURITY DEVICES, LIFE SUPPORT PRODUCTS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF CIRRUS PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD
TO BE FULLY AT THE CUSTOMER’S RISK AND CIRRUS DISCLAIMS AND MAKES NO WARRANTY, EXPRESS, STATUTORY OR IMPLIED, INCLUDING THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR PARTICULAR PURPOSE, WITH REGARD TO ANY CIRRUS PRODUCT THAT IS USED
IN SUCH A MANNER. IF THE CUSTOMER OR CUSTOMER’S CUSTOMER USES OR PERMITS THE USE OF CIRRUS PRODUCTS IN CRITICAL APPLICATIONS, CUSTOMER AGREES, BY SUCH USE, TO FULLY INDEMNIFY CIRRUS, ITS OFFICERS, DIRECTORS, EMPLOYEES, DISTRIBUTORS AND OTHER
AGENTS FROM ANY AND ALL LIABILITY, INCLUDING ATTORNEYS’ FEES AND COSTS, THAT MAY RESULT FROM OR ARISE IN CONNECTION WITH
THESE USES.
Cirrus Logic, Cirrus, the Cirrus Logic logo designs, and Popguard are trademarks of Cirrus Logic, Inc. All other brand and product names in this document may be
trademarks or service marks of their respective owners.
I²C is a trademark of Philips Semiconductor.
SPI is a trademark of Motorola, Inc.
DS686F1
45