CS4270-CZZR - Cirrus Logic - Datasheet.Directory

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24-Bit, 192-kHz Stereo Audio CODEC

D/A Features

High Performance

– 105 dB Dynamic Range

– -87 dB THD+N

Selectable Serial Audio Interface Formats

– Left-Justified up to 24 bits

– I²S up to 24 bits

– Right-Justified 16, and 24 bits

Control Output for External Muting

Digital De-Emphasis

Popguard® Technology

Multi-bit  Conversion

Digital Volume Control

Single-Ended Output

A/D Features

High Performance

– 105 dB Dynamic Range

– -95 dB THD+N

Multi-bit Conversion

High-Pass Filter to Remove DC Offsets

Selectable Serial Audio Interface Formats

– Left-Justified up to 24 bits

– I²S up to 24 bits

Single-Ended Input

System Features

Direct Interface with Logic Levels 1.8 V to 5 V

Internal Digital Loopback

Stand-Alone or Serial Control Port Functionality

Single-Ended Analog Architecture

Supports all Audio Sample Rates from 4 kHz to

216 kHz

3.3- or 5-V Core Supply

Internal Voltage

Reference

Software or

Stand-Alone

Configuration

Analog Out A

(Left)

PCM Serial

Audio Input

Volume

Control

ADC

Digital

Filter

Multi-bit

Modulator

External Mute

Control Mute Signals

PCM Serial

Audio Output

Configuration

Registers

Serial

Audio

Input

Level

Translators

Volume

Control

Serial

Audio

Output

High Pass

Filter

High Pass

Filter

Multi-bit

Modulator

ADC

Digital

Filter

Switch-Cap

DAC and

Analog Filter

Switch-Cap

DAC and

Analog Filter

____

RST

VLC

1.8 V to 5 V

Switch-Cap

ADC

Switch-Cap

ADC

DAC

Digital

Filter

DAC

Digital

Filter

3.3 V to 5 V

Analog Out B

(Right)

Analog Input A

(Left)

Analog Input B

(Right)

AUGUST '10

DS686F1

CS4270

2DS686F1

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

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

– Selectable High-Pass Filter or DC Offset

Calibration

– Selectable Serial Audio Interface Formats

• Left-Justified up to 24-bit

• I²S up to 24-bit

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 sam-

pling 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 be-

tween the CS4270 and other devices operating over a

wide range of logic levels.

Independently addressable high-pass filters are avail-

able 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 Demonstra-

tion 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 distor-

tion, and low noise make it ideal for applications such as

DVD recorders, digital televisions, set-top boxes, and

effects processors.

DS686F1 3

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

4DS686F1

CS4270

1. PIN DESCRIPTIONS

1.1 Software Mode

Pin Name # 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 serial audio

data line. The frequency of the left/right clock must be at the audio sample rate, Fs.

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.

SDA/CDOUT 9 Serial Control Data (Input/Output) - SDA is a data I/O line in I²C Mode. CDOUT is the output data line for the

Serial Control Port in SPI format.

SCL/CCLK 10 Serial Control Port Clock (Input) - SCL is the serial input Clock for the Serial Control Port in I²C format. CCLK

is the serial input Clock for the Serial Control Port in SPI format.

AD0/CS 11 Address Bit 0 (I²C)/Serial Control Port Chip Select (SPI) (Input) - AD0 is a chip address pin in I²C format.

CS is the chip select signal for SPI format.

AD1/CDIN 12 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.

AD2 13 Address Bit 2 (I²C) (Input) - AD2 is a chip address pin in I²C format.

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

16 Analog Audio 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

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

23 Analog Audio Output (Output) - Analog outputs from the DAC.

SDIN

LRCK

MCLK

SCLK

DGND

SDOUT

VLC

SDA/CDOUT

SCL/CCLK

AD0/CS

AD1/CDIN

MUTEB

AOUTB

AOUTA

MUTEA

AGND

FILT+

AINB

AINA

RST

AD2

DS686F1 5

CS4270

1.2 Stand-Alone Mode

Pin Name # 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)7Serial 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.

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

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

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

Mute Control (Output) - Mute control signal used to control the state of the optional external analog mut-

ing circuitry. See Section 5.6 on page 27.

AOUTA

AOUTB

23 Analog Audio Output (Output) - Analog outputs for the DAC.

SDIN

LRCK

MCLK

SCLK

DGND

SDOUT

VLC

I²S/LJ

MDIV1

MUTEB

AOUTB

AOUTA

MUTEA

AGND

FILT+

AINB

AINA

RST

MDIV2

6DS686F1

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

Supply

Number

Pin Name I/O Driver Receiver

Software Mode

VLC

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

Stand-Alone Mode

VLC

9 M1 Input - 1.8 V-5.0 V

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

All Modes

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 -

Table 1. Digital I/O Pin Power Rails

DS686F1 7

CS4270

3. TYPICAL CONNECTION DIAGRAM

Figure 1. CS4270 Typical Connection Diagram

CS (I2S/LJ) /AD0

SDA/CDOUT (M1)

SCL/CCLK (M0)

AINA

AINB

RST

Power

Down

and Mode

Settings

(Control Port)

AOUTA

MUTEA

AOUTB

MUTEB

Analog Output

Network

and Mute

LRCK

SCLK

MCLK Timing Logic

and

Clocks

SDIN

)S(M/SDOUT Audio Data

Processor

DGND

FILT+

AGND

+3.3 V to 5 V

CS4270

GND or VD

47 k

5.1

Analog Input

Network

47 µF 0.1 µF

10 µF 0.1 µF

1 µF0.1 µF

1 µF

If using separate supplies for

VA and VD, 5.1 resistor not

needed. See "Grounding and

Power Supply Decoupling."

VLC

+1.8 V to 5 V

3. Use pull-up resistors in Software

Mode. In Stand-Alone Mode, use

pull-up or pull-down. See "Mode

Selection & De-Emphasis."

2 k

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."

AD1/CDIN (MDIV2)

AD2 (MDIV1)

0.1 µF

8DS686F1

CS4270

4. CHARACTERISTICS AND SPECIFICATIONS

SPECIFIED OPERATING CONDITIONS

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

ABSOLUTE MAXIMUM RATINGS

AGND = DGND = 0 V, All voltages with respect to ground.(Note 1)

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.

Parameters Symbol Min Nom Max Units

DC Power Supplies: Analog

Digital

Serial Control Port

VLC

3.14

1.71

5.0

3.3

5.25

Ambient Operating Temperature (Power Applied) TA-40 - +85 C

Parameter Symbol Min Typ Max Units

DC Power Supplies: Analog

Digital

Serial Control Port

VLC

-0.3

+6.0

Input Current (Note 2) Iin -10 - 10 mA

Analog Input Voltage VIN AGND-0.7 - VA+0.7 V

Digital Input Voltage Serial Control Port

Digital

VIND-C

VIND-D

-0.3

VLC+0.3

VD+0.3

Ambient Operating Temperature (Power Applied) TAC -50 - +95 C

Storage Temperature Tstg -65 - +150 C

DS686F1 9

CS4270

DAC ANALOG CHARACTERISTICS

Test Conditions (unless otherwise specified): VD = VL = 3.3 V, AGND = DGND = 0 V; TA = +25° C; Full-Scale Out-

put 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.

Note: 3. One LSB of triangular PDF dither added to data.

Parameter Symbol

VA = 5 V VA = 3.3 V

UnitMin Typ Max Min Typ Max

Dynamic Range 18 to 24 bit A-weighted

unweighted

16 Bit A-weighted

unweighted

105

102

103

100

Total Harmonic Distortion + Noise

18 to 24 bit 0 dB

-20 dB

-60 dB

16 Bit 0 dB

-20 dB

-60 dB

THD+N

-87

-82

-42

-85

-76

-36

-83

-81

-83

-80

-40

-81

-76

-36

-79

-77

DAC Performance across Full VA Range

Parameter Symbol Min Typ Max Unit

Interchannel Isolation (1 kHz) - 100 - dB

DC Accuracy

Interchannel Gain Mismatch - 0.1 0.25 dB

Gain Drift -100 - +100 ppm/°C

Analog Output

Full Scale Output Voltage 0.6•VA 0.65•VA 0.7•VA Vpp

Max DC Current draw from AOUTA or AOUTB IOUTmax -10-A

Max AC-Load Resistance (see Figure 3)R

L-3-k

Max Load Capacitance (see Figure 3)C

L-100-pF

Output Impedance of AOUTA and AOUTB ZOUT -100-

AOUTx

AGND

3.3 µF

Vout

RLCL

100

2.5

51015

Safe Operating

Region

Capacitive Load -- C (pF)

Resistive Load -- R (k



)

125

Figure 2. Output Test Load Figure 3. Maximum Loading

10 DS686F1

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 sam-

ple rate by multiplying the given characteristic by Fs. (See Note 4)

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.

Parameter Symbol Min Typ Max Unit

Single-Speed Mode

Passband (Note 5) to -0.1 dB corner

to -3 dB corner

.35

.4992

Frequency Response 10 Hz to 20 kHz -.175 - +.01 dB

StopBand .5465 - - Fs

StopBand Attenuation (Note 6) 50 - - dB

Group Delay tgd - 10/Fs - s

De-emphasis Error (Note 8) Fs = 32 kHz

Fs = 44.1 kHz

Fs = 48 kHz

+1.5/+0

+.05/-.25

-.2/-.4

Double-Speed Mode

Passband (Note 5) to -0.1 dB corner

to -3 dB corner

.22

.501

Frequency Response 10 Hz to 20 kHz -.15 - +.15 dB

StopBand .5770 - - Fs

StopBand Attenuation (Note 6) 55 - - dB

Group Delay tgd - 5/Fs - s

Quad-Speed Mode

Passband (Note 5) to -0.1 dB corner

to -3 dB corner

0.110

0.469

Frequency Response 10 Hz to 20 kHz -.12 - +0 dB

StopBand 0.7 - - Fs

StopBand Attenuation (Note 6) 51 - - dB

Group Delay tgd - 2.5/Fs - s

DS686F1 11

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.

Note: 8. Referred to the typical full-scale input voltage.

Dynamic Performance VA = 5 V VA = 3.3 V

Single-Speed Mode Fs = 48 kHz Symbol Min Typ Max Min Typ Max Unit

Dynamic Range A-weighted

unweighted

105

102

Total Harmonic Distortion + Noise (Note 8)

-1 dB

-20 dB

-60 dB

THD+N -

-95

-82

-42

-90

-92

-79

-39

-87

Double-Speed Mode Fs = 96 kHz

Dynamic Range A-weighted

unweighted

40 kHz bandwidth unweighted

105

102

Total Harmonic Distortion + Noise (Note 8)

-1 dB

-20 dB

-60 dB

40 kHz bandwidth unweighted

THD+N

-95

-82

-42

-93

-90

-92

-79

-39

-89

-87

Quad-Speed Mode Fs = 192 kHz

Dynamic Range A-weighted

unweighted

40 kHz bandwidth unweighted

105

102

Total Harmonic Distortion + Noise (Note 8)

-1 dB

-20 dB

-60 dB

40 kHz bandwidth -1 dB

THD+N

-95

-82

-42

-93

-90

-92

-79

-39

-89

-87

Dynamic Performance - All Sampling Speed Modes

Parameter Min Typ Max Unit

Interchannel Isolation - 100 - dB

DC Accuracy

Interchannel Gain Mismatch - 0.1 - dB

Gain Error -3 - +3 %

Gain Drift - 100 - ppm/°C

Analog Input Characteristics

Full-Scale Input Voltage 0.53*VA 0.56*VA 0.58*VA Vpp

Input Impedance - 300 - k

12 DS686F1

CS4270

ADC DIGITAL FILTER CHARACTERISTICS

Measurement Bandwidth is 10 Hz to 20 kHz unless otherwise specified. (Note 9)

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.

Parameter Symbol Min Typ Max Unit

Single-Speed Mode

Passband (-0.1 dB) (Note 10) 0-0.49Fs

Passband Ripple - - 0.035 dB

Stopband (Note 10) 0.57 - - Fs

Stopband Attenuation 70 - - dB

Group Delay tgd - 12/Fs - s

Double-Speed Mode

Passband (-0.1 dB) (Note 10) 0-0.49Fs

Passband Ripple - - 0.05 dB

Stopband (Note 10) 0.56 - - Fs

Stopband Attenuation 69 - - dB

Group Delay tgd -9/Fs- s

Quad-Speed Mode

Passband (-0.1 dB) (Note 10) 0-0.26Fs

Passband Ripple - - 0.05 dB

Stopband (Note 10) 0.50 - - Fs

Stopband Attenuation 60 - - dB

Group Delay tgd -5/Fs- s

High-Pass Filter Characteristics

Frequency Response -3.0 dB

-0.13 dB (Note 11)

Phase Deviation @ 20 Hz (Note 11) - 10 - deg

Passband Ripple --0dB

DS686F1 13

CS4270

DC ELECTRICAL CHARACTERISTICS

TA = 25° C; AGND = DGND = 0 V, all voltages with respect to 0 V; MCLK = 12.288 MHz; Master Mode).

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

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

Parameter Symbol Min Typ Max Unit

Power Supply

Power Supply Current VA = 5 V

(Normal Operation) VA = 3.3 V

VD, VLC = 5 V

VD, VLC = 3.3 V

Power Supply Current VA = 5 V

(Power-Down Mode) (Note 12) VD, VLC = 5 V

A

Power Consumption

VA = 5 V, VD = VLC= 3.3 V Normal Operation

VA = 5 V, VD = VLC = 5 V Normal Operation

Power-Down Mode (Note 12)

224

345

365

270

400

W

Power Supply Rejection Ratio(1 kHz) (Note 13) PSRR - 55 - dB

Common Mode Voltage

Nominal Common Mode Voltage VQ - VA/2 - VDC

Maximum DC Current Source/Sink from VQ - 1 - A

VQ Output Impedance - 25 - k

Positive Voltage Reference

FILT+ Nominal Voltage FILT+ - VA - VDC

Maximum DC Current Source/Sink from FILT+ - 10 - A

FILT+ Output Impedance - 10 - k

Mute Control

Maximum MUTEA & MUTEB Drive Current - 3 - mA

Parameter (Note 14) Symbol Min Typ Max Units

High-Level Input Voltage Serial Audio Interface

Serial Control Port VIH

0.7xVD

0.7xVLC

Low-Level Input Voltage Serial Audio Interface

Serial Control Port VIL

0.2xVD

0.2xVLC

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

Low-Level Output Voltage at Io = 2 mA VOL --0.4V

Input Leakage Current Iin -10 - 10 A

14 DS686F1

CS4270

SWITCHING CHARACTERISTICS - SERIAL AUDIO INTERFACE

Logic "0" = DGND = AGND = 0 V; Logic "1" = VD, CL = 20 pF.

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.

Parameter Symbol Min Typ Max Unit

Sample Rate Single-Speed Mode

Double-Speed Mode

Quad-Speed Mode

100

108

216

kHz

MCLK Specifications

MCLK Frequency Stand-Alone Mode

(Note 15) Serial Control Port Mode

fmclk

1.024

55.296

MHz

MCLK Duty Cycle 405060ns

Master Mode

LRCK Duty Cycle - 50 - %

SCLK Period (Note 16) tsclkw --s

SCLK Duty Cycle - 50 - %

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

Slave Mode

LRCK Duty Cycle 40 50 60 %

SCLK Period

(Note 15) Single-Speed Mode

Double-Speed Mode

Quad-Speed Mode

tsclkw

SCLK Duty Cycle 455055ns

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

64Fs

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

128Fs

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

64Fs

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

64Fs

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

DS686F1 15

CS4270

Figure 4. Master Mode, Left-Justified SAI Figure 5. Slave Mode, Left-Justified SAI

SCLK output

SDOUT

LRCK output

MSB MSB-1 MSB-2 MSB-3

tmslr

tsdo

LRCK input

SCLK input

SDOUT MSB

tstp thld

tsclkl

tsclkh

MSB-1

tslrd

SCLK output

SDOUT

LRCK output

MSB MSB-1 MSB-2 MSB-3

tsdo

tmslr

LRCK input

SCLK input

SDOUT

tstp thld

tsclkl

tsclkh

MSB

tslrd

Figure 6. Master Mode, I²S SAI Figure 7. Slave Mode, I²S SAI

sdis

SCLK

SDIN

sdih

sclkw

Figure 8. Master and Slave Mode, SCLK/SDIN

16 DS686F1

CS4270

Figure 9. Format 0, Left-Justified up to 24-Bit Data

LRCK

SCLK

Channel A - Left

SDATA +3 +2 +1 LSB

+5 +4

MSB -1 -2 -3 -4 -5 +3 +2 +1 LSB

+5 +4

MSB -1 -2 -3 -4

Channel B - Right

Figure 10. Format 1, I²S up to 24-Bit Data

LRCK

SCLK

SDINx +3 +2 +1+5 +4

-1 -2 -3 -4 -5 +3 +2 +1+5 +4

-1 -2 -3 -4

MSB MSB

LSB LSB

Channel A - Left Channel B - Right

LRCK

SCLK

SDATA +5 +4 +3 +2 +1

MSB -1 -2 -3 -4 -5

32 clocks

Right Channel

LSB +5 +4 +3 +2 +1

-1 -2 -3 -4 -5

-6 +6

-6

Channel B - Right

LSB MSB LSB

Channel A - Left

Figure 11. Format 2 or 3, Right-Justified 16-Bit or 24-Bit Data (Serial Control Port Mode Only)

DS686F1 17

CS4270

SWITCHING CHARACTERISTICS - SOFTWARE MODE - I²C FORMAT

Inputs: Logic ‘0’ = AGND = DGND = 0 V, Logic ‘1’ = VLC, CL=30pF

Note: 17. Data must be held for sufficient time to bridge the transition time, tfc, of SCL.

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

Rise Time of SCL and SDA trc -1µs

Fall Time SCL and SDA tfc -300ns

Setup Time for Stop Condition tsusp 4.7 - µs

Acknowledge Delay from SCL Falling tack 300 1000 ns

tbuf thdst

tlow thdd

thigh

tsud

Stop Start

SDA

SCL

tirs

RST

thdst

trc

tfc

tsust

tsusp

Start Stop

Repeated

trd tfd

tack

Figure 12. Software Mode Timing - I²C Format

18 DS686F1

CS4270

SWITCHING CHARACTERISTICS - SOFTWARE MODE - SPI FORMAT

Inputs: Logic ‘0’ = AGND = DGND = 0 V; Logic ‘1’ = VLC; CL=20pF.

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.

Figure 13. SPI Control Port Timing

Parameter Symbol Min Max Unit

CCLK Clock Frequency fsclk -6MHz

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

tr2 tf2

tdsu tdh

tsch

tscl

CCLK

CDIN

tcss tcsh

tspi

tsrs

RST

CDOUT

tscdov tscdov tcscdo

Hi-Impedance

DS686F1 19

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 config-

uration 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 peri-

ods. Table 2 lists the approximate wait time for each sampling 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.

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

Mode Sampling Frequency

Single-Speed 4-54 kHz

Double-Speed 50-108 kHz

Quad-Speed 100-216 kHz

Table 3. Speed Modes

20 DS686F1

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.

5.1.5 Interpolation Filter

In Stand-Alone Mode, the fast roll-off interpolation filter is used. Filter specifications can be found in Sec-

tion 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

Master Mode

MCLK/LRCK SCLK/LRCK LRCK MDIV2 MDIV1

Single-Speed

256 64 Fs 0 0

384 (Note 22) 64 Fs 0 1

512 64 Fs 1 0

1,024 64 Fs 1 1

Double-Speed

128 64 Fs 0 0

192 (Note 22) 64 Fs 0 1

256 64 Fs 1 0

512 64 Fs 1 1

Quad-Speed

64 64 Fs 0 0

96 (Note 22) 64 Fs 0 1

128 64 Fs 1 0

256 64 Fs 1 1

Slave Mode

MCLK/LRCK SCLK/LRCK LRCK MDIV2 MDIV1

Single-Speed

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

Double-Speed

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

Quad-Speed

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: 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.

DS686F1 21

CS4270

could result in recording a DC level, possibly yielding "clicks" when switching between devices in a multi-

channel 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.

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 config-

uration 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 power-

down 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.

Mode 1 Mode 0 Mode Sample Rate (Fs) De-Emphasis

00 Single-Speed 4 kHz - 54 kHz Off

01 Single-Speed 4 kHz - 54 kHz 44.1 kHz

10 Double-Speed 50 kHz - 108 kHz Off

11 Quad-Speed 100 kHz - 216 kHz Off

Table 5. CS4270 Stand-Alone Mode Control

22 DS686F1

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.

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.

Mode Sampling Frequency

Single-Speed 4-54 kHz

Double-Speed 50-108 kHz

Quad-Speed 100-216 kHz

Table 6. Speed Modes

Master Mode

Speed Mode MCLK/LRCK SCLK/LRCK LRCK MCLK_FREQ2 MCLK_FREQ1 MCLK_FREQ0

Single-Speed

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

Double-Speed

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

Quad-Speed

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

DS686F1 23

CS4270

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 ac-

cording 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 multi-

channel 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.

Slave Mode

Speed Mode MCLK/LRCK SCLK/LRCK LRCK MCLK_FREQ2 MCLK_FREQ1 MCLK_FREQ0

Single-Speed

256 32, 48, 64, 128 Fs 0 0 0

384 32, 48, 64, 96, 128 Fs 0 0 1

512 32, 48, 64, 128 Fs 0 1 0

768 32, 48, 64, 96, 128 Fs 0 1 1

1,024 32, 48, 64, 96, 128 Fs 1 0 0

Double-Speed

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

Quad-Speed

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)

24 DS686F1

CS4270

5.2.8 Oversampling Modes

The CS4270 operates in one of three oversampling modes based on the input sample rate. Mode selec-

tion 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 in-

put 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 power-

down. 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 Pop-

guard 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 volt-

age. 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 dis-

charge. 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 be-

fore 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.

DS686F1 25

CS4270

5.5 Analog Connections

The analog modulator samples the input at 6.144 MHz for Fs = 48, 96, and 128 kHz and scales propor-

tionally for all other sampling speeds.The digital filter rejects signals within the stopband of the filter. How-

ever, 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 modu-

lator sampling frequency, but to act as a charge source for the internal sampling circuits. The use of ca-

pacitors 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 deter-

mine the values of resistors R1 and R2, as seen in Figure 15, and shows the design equations used to

determine these values.

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.

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.

Attenuation: The required attenuation factor depends on the magnitude of the input sig-

nal. 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 equa-

tions.

Table 8. Analog Input Design Parameters

Gain

-10dB

0dB

Frequency

T2 = 15 µs

T1=50 µs

F1 F2

3.183 kHz 10.61 kHz

Figure 14. De-Emphasis Curve

R1R2

R1R2+

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

R2

R1R2+

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

R1R2+

26 DS686F1

CS4270

220 pF

Analog

Input

10 µF

AINx

CS4270

2 k

(R1)

2 k

(R2)

Figure 15. CS4270 Example Analog Input Network

110

-110

-105

-100

-95

-90

-85

-80

-75

-70

-65

-60

ADC Source Impedance (kOhms)

ADC THD+N @ 1kHz

Figure 16. A/D THD+N Performance vs. Input Source Impedance

(k )

110 100

100

102

104

106

ADC Source Impedance (kOhms)

ADC Dynamic Range

Figure 17. A/D Dynamic Range vs. Input Source Impedance

(k )

DS686F1 27

CS4270

5.5.2 Output Connections

The analog output filter present in the CS4270 is a switched-capacitor low pass filter. Its response, com-

bined with that of the digital interpolator, is given in Figures 23 - 46. The recommended external analog

circuitry is shown in Figure 18.

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 min-

imum 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.

Figure 18. CS4270 Recommended Analog Output Filter

Analog Output

R+ 470

C= 4F

s(R 470 )

3.3 µF

10 k

470 

Rext

ext

AOUTx

CS4270

LPF

-V

560 Audio

Out

2 k

10 k

-V

+VA

MMUN2111LT1

AOUTx

CS4270

Couple

47 k

MUTEx

Figure 19. Suggested Active-Low Mute Circuit

28 DS686F1

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. Pow-

er 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, partic-

ularly 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 oper-

ational 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 de-

fined 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 Point-

er (MAP) which selects the register to be read or written. If the operation is a read, the contents of the reg-

ister 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.

DS686F1 29

CS4270

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 con-

dition. 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 spec-

ifications in “Switching Characteristics - Software Mode - SPI Format” section on page 18.

4 5 6 7 24 25

SCL

CHIP ADDRESS (WRITE) MAP BYTE DATA DATA +1

START

ACK

STOP

ACKACKACK

1 0 0 1 1 AD1 AD0 0

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

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

DATA +n

Figure 20. Software Mode Timing, I²C Write

SCL

CHIP ADDRESS (WRITE) MAP BYTE DATA DATA +1

START

ACK

STOP

ACK

1 0 0 1 0 AD1 AD0 0

SDA 1 0 0 1 0 AD1 AD0 1

CHIP ADDRESS (READ)

START

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

168 9 12 13 14 154 5 6 7 0 1 20 21 22 23 24 26 27 28

2 3 10 11 17 18 19 25

ACK

DATA + n

STOP

Figure 21. Software Mode Timing, I²C Read

30 DS686F1

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.

MAP

MSB LSB

DATA

byte 1 byte n

R/W R/W

ADDRESS

CHIP

ADDRESS

CHIP

MSB LSB MSB LSB

MAP = Memory Address Pointer, 8 bits, MSB first

High Impedance

1001111 1001111

CCLK

CDIN

CDOUT

Figure 22. Software Mode Timing, SPI Mode

DS686F1 31

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 7 6 5 4 3 2 1 0

01h Device ID ID3 ID2 ID1 ID0 REV3 REV2 REV1 REV0

p32 1100000 1

02h Power Control Freeze Reserved PDN_ADC Reserved Reserved Reserved PDN_DAC PDN

p32 0000000 0

03h Mode Control Reserved Reserved FM1 FM0 MCLK_

FREQ2

MCLK_

FREQ1

MCLK_

FREQ0 POPG

p33 0011000 0

04h ADC and DAC

Control

ADC_HPF_

FRZ_A

ADC_HPF_

FRZ_B

DIG_

LOOPBK DAC_DIF1 DAC_DIF0 Reserved Reserved ADC_DIF0

p34 0000000 0

05h Transition

Control

DAC_SNGL_

VOL DAC_SOFT DAC_ZC ADC_INV_

ADC_INV_

DAC_INV_

BDAC_INV_A DE_EMPH

p35 0110000 0

06h Mute Control Reserved Reserved AUTO_

MUTE

MUTE_

ADC_CHB

MUTE_

ADC_CH A

MUTE_

POL

MUTE_DAC_

CHB

MUTE_DAC_

CHA

p36 0010000 0

07h DAC Channel A

Volume Control

DACA_

VOL7

DACA_

VOL6

DACA_

VOL5

DACA_

VOL4

DACA_

VOL3

DACA_

VOL2

DACA_

VOL1

DACA_

VOL0

p36 0000000 0

08h DAC Channel B

Volume Control

DACB_

VOL7

DACB_

VOL6

DACB_

VOL5

DACB_

VOL4

DACB_

VOL3

DACB_

VOL2

DACB_

VOL1

DACB_

VOL0

p37 0000000 0

32 DS686F1

CS4270

8. REGISTER DESCRIPTION

** All registers are read/write in I²C Mode and SPI Mode, unless otherwise noted**

8.1 Device ID - Address 01h

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

8.2.1 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.

76543210

ID3 ID2 ID1 ID0 REV3 REV2 REV1 REV0

76543210

Freeze Reserved PDN_ADC Reserved Reserved Reserved PDN_DAC PDN

DS686F1 33

CS4270

8.3 Mode Control - Address 03h

8.3.1 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.

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.

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.

7654321 0

Reserved Reserved FM1 FM0 MCLK_FREQ2 MCLK_FREQ1 MCLK_FREQ0 POPG

FM1 FM0 Mode

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

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

34 DS686F1

CS4270

8.4 ADC and DAC Control - Address 04h

8.4.1 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 con-

tinuously subtracted from the conversion result. To recalibrate ADC channel A and obtain a new or con-

tinuous 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.

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.

76543210

ADC_HPF_

FRZ_A

ADC_HPF_

FRZ_B

DIG_

LOOPBK DAC_DIF1 DAC_DIF0 Reserved Reserved ADC_DIF0

DAC_DIF1 DAC_DIF0 Description Format Figure

0 0 Left Justified, up to 24-bit data (default) 0 9

0 1 I²S, up to 24-bit data 1 10

1 1 Right-Justified, 16-bit Data 2 11

1 0 Right-Justified, 24-bit Data 3 11

Table 11. DAC Digital Interface Formats

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

DS686F1 35

CS4270

8.5 Transition Control - Address 05h

8.5.1 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 ramp-

ing, 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 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.

Soft Ramp and Zero Cross Enable

Soft Ramp and Zero Cross Enable dictate that signal level changes, either by attenuation changes or mut-

ing, 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 sam-

ple rate) if the signal does not encounter a zero crossing. The zero cross function is independently mon-

itored and implemented for each channel. See Table 10 on page 33.

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.

76543210

DAC_SNGL_

VOL DAC_SOFT DAC_ZC ADC_INV_

CHB

ADC_INV_

CHA

DAC_INV_

CHB

DAC_INV_

CHA DE_EMPH

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

36 DS686F1

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

8.6.1 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

Function:

See Section 8.8 DAC Channel B Volume Control - Address 08h.

76543210

Reserved Reserved AUTO_MUTE MUTE_ADC_

CHB

MUTE_ADC_

CHA MUTE_POL MUTE_DAC_

CHB

MUTE_DAC_

CHA

76543210

DACA_

VOL7

DACA_

VOL6

DACA_

VOL5

DACA_

VOL4

DACA_

VOL3

DACA_

VOL2

DACA_

VOL1

DACA_

VOL0

DS686F1 37

CS4270

8.8 DAC Channel B Volume Control - Address 08h

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 at-

tenuation 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).

76543210

DACB

VOL7

DACB

VOL6

DACB

VOL5

DACB

VOL4

DACB

VOL3

DACB

VOL2

DACB

VOL1

DACB

VOL0

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

38 DS686F1

CS4270

9. FILTER PLOTS

Figure 23. DAC Single-Speed Stopband Rejection Figure 24. DAC Single-Speed Transition Band

0.45 0.46 0.47 0.48 0.49 0.5 0.51 0.52 0.53 0.54 0.5

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

Frequency (normalized to Fs)

Amplitude dB

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

-0.25

-0. 2

-0.15

-0. 1

-0.05

0.05

Frequency (normalized to Fs)

Amplitude dB

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 39

CS4270

0.45 0.46 0.47 0.48 0.49 0.5 0.51 0.52 0.53 0.54 0.55

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

Frequency (normalized to Fs)

Amplitude dB

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

-0. 2

-0. 1

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Frequency (normalized to Fs)

Amplitude dB

Figure 29. DAC Double-Speed Transition Band (detail) Figure 30. DAC Double-Speed Passband Ripple

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

Amplitude (dB)

Frequency(normalized to Fs)

0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75

-60

-50

-40

-30

-20

-10

Amplitude (dB)

Frequency(normalized to Fs)

Figure 31. DAC Quad-Speed Stopband Rejection Figure 32. DAC Quad-Speed Transition Band

0.4 0.45 0.5 0.55 0.6 0.65 0.7

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

Amplitude (dB)

Frequency(normalized to Fs)

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

-1. 5

-1

-0. 5

Frequency (normalized to Fs)

Amplitude dB

Figure 33. DAC Quad-Speed Transition Band (detail) Figure 34. DAC Quad-Speed Passband Ripple

40 DS686F1

CS4270

Figure 35. ADC Single-Speed Stopband Rejection Figure 36. ADC Single-Speed Stopband (detail)

-140

-130

-120

- 110

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0.0 0.1 0 .2 0.3 0 .4 0.5 0.6 0.7 0.8 0 .9 1.0

Frequency (normalized to Fs)

Amplitude (dB)

-140

-130

-120

- 110

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0.40 0.42 0.44 0.46 0.48 0.50 0.52 0.54 0.56 0.58 0.60

Frequency (normalized to Fs)

Amplitude (dB)

Figure 37. ADC Single-Speed Transition Band (detail) Figure 38. ADC Single-Speed Passband Ripple

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0.45 0.46 0.47 0.48 0.49 0.5 0.51 0.52 0.53 0.54 0.55

Frequency (normalized to Fs)

Amplitude (dB)

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

0.02

0.04

0.06

0.08

0.10

0 0.050.10.150.20.250.30.350.40.450.5

Frequency (normalized to Fs)

Amplitude (dB)

Figure 39. ADC Double-Speed Stopband Rejection Figure 40. ADC Double-Speed Stopband (detail)

-140

-130

-120

- 110

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0.0 0.1 0 .2 0.3 0 .4 0.5 0.6 0.7 0.8 0 .9 1.0

Frequency (normalized to Fs)

Amplitude (dB)

-140

-130

-120

- 110

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0.40 0.42 0.44 0.46 0.48 0.50 0.52 0.54 0.56 0.58 0.60

Frequency (normalized to Fs)

Amplitude (dB)

DS686F1 41

CS4270

Figure 41. ADC Double-Speed Transition Band (detail) Figure 42. ADC Double-Speed Passband Ripple

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0.46 0.47 0.48 0.49 0.50 0.51 0.52

Frequency (normalized to Fs)

Amplitude (dB)

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

0.02

0.04

0.06

0.08

0.10

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50

Frequency (normalized to Fs)

Amplitude (dB)

Figure 43. ADC Quad-Speed Stopband Rejection Figure 44. ADC Quad-Speed Stopband (detail)

-140

-130

-120

- 110

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0.0 0.1 0 .2 0.3 0 .4 0.5 0.6 0.7 0.8 0 .9 1.0

Frequency (normalized to Fs)

Amplitude (dB)

-140

-130

-120

- 110

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

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

Frequency (normalized to Fs)

Amplitude (dB)

Figure 45. ADC Quad-Speed Transition Band (detail) Figure 46. ADC Quad-Speed Passband Ripple

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50

Frequency (normalized to Fs)

Amplitude (dB)

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

0.02

0.04

0.06

0.08

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 (normalized to Fs)

Amplitude (dB)

42 DS686F1

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 Ja-

pan, 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.

DS686F1 43

CS4270

11.PACKAGE DIMENSIONS

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 re-

duce 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

4. JA is specified according to JEDEC specifications for multi-layer PCBs.

INCHES MILLIMETERS NOTE

DIM MIN NOM MAX MIN NOM MAX

A----0.47----1.20

A1 0.00197 0.00394 0.00591 0.05 0.10 0.15

A2 0.03150 0.0394 0.04137 0.80 1.00 1.05

b 0.00748 0.00965 0.01182 0.19 0.245 0.30 2,3

D 0.30338 BSC 0.30732 BSC 0.31126 BSC 7.70 BSC 7.80 BSC 7.90 BSC 1

E 0.24822 0.25216 0.25610 6.30 6.40 6.50

E1 0.16942 0.17336 0.17730 4.30 4.40 4.50 1

e -- 0.026 BSC -- -- 0.65 BSC --

L 0.01970 0.02364 0.02955 0.50 0.60 0.75

µ0° 4° 8° 0° 4° 8°

JEDEC #: MO-153

Controlling Dimension is Millimeters.

Parameters Symbol Min Typ Max Units

Allowable Junction Temperature - - 135 C

Junction to Ambient Thermal Impedance (Note 4)

(Multi-layer PCB) TSSOP

(Single-layer PCB) TSSOP

JA-M

JA-S

105

C/W

24L TSSOP (4.4 mm BODY) PACKAGE DRAWING

123

eb2A1

A2 A

SEATING

PLANE

E11

SIDE VIEW

END VIEW

TOP VIEW



44 DS686F1

CS4270

12.ORDERING INFORMATION

13.REVISION HISTORY

Product Description Package Pb-Free Temp Range Container Order #

CS4270 24-Bit 192 kHz Stereo Audio CODEC 24-TSSOP YES -10° to +70° C Rail CS4270-CZZ

Tape & Reel CS4270-CZZR

CDB4270 CS4270 Evaluation Board -- - -CDB4270

Release Changes

– 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 45

CS4270

Contacting Cirrus Logic Support

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To find the one nearest to you, go to www.cirrus.com.

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