OVERVIEWCS42L73 is a highly integrated, low-power, mobile audio distribution network that incorporates two stereo DACs and a stereo ADC with ground centered headphone, line and speaker amplifiers for smartphone and portable applications. Three asynchronous bidirectional serial ports with integrated asynchronous sample rate converters (ASRCs) that accept a wide range of incoming audio sample rates can be used to feed the integrated digital mixing engine, which is the heart of the CS42L73. The engine can simultaneously overlay and distribute digital audio from up to three external sources to any of its integrated audio nodes, giving complete routeability to the mobile system designer.

The analog audio peripherals, fed by the digital mixing engine of the CS42L73, routing into two stereo high performance DACs is designed with the smartphone in mind. Additional considerations include an integrated MIC bias to support the high performance stereo ADCs, as well as the first digital MIC input to a Cirrus Logic general market codec. Features such as a 1 VRMS line level output from a single 1.8 V power supply, and an on-board tri-level inverting charge pump capable of driving a headphone load with the lowest DC offset on the market contribute to the unique value of the CS42L73. The CS42L73 offers the lowest power consumption of any audio codec with integrated bi-directional SRCs. From the serial port to the stereo headphone load via the digital mixing engine and the SRCs, the CS42L73 burns only 3.5 mW in real world conditions.

CS42L73 HIgHLy IntEgRatEd LOW POWER MObILE StEREO COdEC

LEaRn MORE at

www.cirrus.com

LOW POWER C O n V E R t E R S

CS42L73 65-baLL Fbga PaCkagE(actual size: 5 mm x 5 mm)

CS42L73 64-baLL WLCSP PaCkagE(actual size: 3.44 mm x 3.44 mm)

MaRkEt aPPLICatIOnS

Smartphones

Mobile Internet Devices

Bluetooth® Headsets

CIRRuS LOgIC, InC.

2901 Via Fortuna

Austin, Texas 78746

United States

T +1-512-851-4000

Toll-Free +1-800-888-5016

SaLES SuPPORt

North America +1 800-625-4084

Asia Pacific +852 2376-0801

Japan +81 (3) 5226-7757

Europe/UK +44 (90) 1628-891-300

Application Processor

MIC (Jack Input )

MIC (Captive)

Main (Ear) Speaker

Hands-Free Speaker

2nd Hands-Free Speaker

Touch Screen

Controller

LCD Controller

Class D Amp

(CS35L01)

Power Management Unit

Baseband Processor

I2S

I2S I2S

Digital Camera

Interface

Line Out

WLAN

A-GPS

Keypad

LCD

Interface

Mobile RF

Low PowerAudio CODEC

(CS42L73)

kEy VaLuESThe CS42L73 can reduce the burden of the system’s applications processor by taking all digital audio sources into a central location, synchronizing the sources and then mixing them for distribution to the audio human interface peripherals. By driving into smaller process nodes the smartphone codec uses lower levels of power consumption than current models which require direct connection to the baseband processor and affords power savings for the overall system when the applications processor is dormant.

SyStEM FEatuRES

Three independent serial ports with •integrated asynch SRCs

Native (no PLL required) support •for 6/12/24 MHz, 13/26 MHz, and 19.2/38.4 MHz master

High-speed I²C™ control port (400 kHz)•

For the full datasheet, visit www.cirrus.com/support.

LOW POWER C O n V E R t E R S | C S 4 2 L 7 3

© 2010 Cirrus Logic, Inc. All rights reserved. Product information is subject to change without notice. Cirrus Logic, Cirrus and the Cirrus Logic logo design

are trademarks of Cirrus Logic, Inc. Other brand and product names may be trademarks or service marks of their respective owners. Product Bulletin 823110-0610-PB

FEatuRESAnAlog I/o

Stereo high performance ADC•91 dB Dynamic Range (A-wtd) G-85 dB THD+N G

Dual digital microphone interface•Independent MIC bias outputs•Stereo DAC to headphone amplifier•

94 dB Dynamic Range (A-wtd) G-81 dB THD+N into 32 G ΩIntegrated Step-down/Inverting Charge Pump G

Class H amplifier - automatic supply adj.•High HP Power Output at -70/-81 dB THD+N G2 x 17/8.5 mW into 16/32 G Ω @ 1.8 V

Stereo DAC to Line Outputs•

Stereo HIgH PerformAnce lIne level DAc97 dB Dynamic Range (A-wtd)•-86 dB THD+N•1 V• RMS from a single 1.8 V power supply

mono DAc to eAr SPeAker AmPlIfIerHigh Power Output at -70 dB (0.032%) THD+N•-45 mW into 16 • Ω @ 1.8 V

mono DAc to SPeAkerPHone AmPlIfIerHigh output power at • ≤ 1% THD+N-1.18/0.84/0.66 W into 8 • Ω @ 5.0/4.2/3.7 VDirect battery-powered operation•

dEMOnStRatIOn bOaRd Cdb42L73

Part

reso

luti

on

(bit

s)

Dyn

amic

ra

nge

(dB

)

tHD

+n (d

B)

Sam

ple

rate

(k

Hz)

Ana

log

out

puts

Pow

er

Supp

ly (v

)

com

men

ts

Pack

age

cS42l73 2491 ADC 97 DAC

–85 48Pseudo

Differential

VA/VCP/VL = 1.66 to 1.94VP = 3.0 to 5.25

VD = 0.85 to 1.40

2 ADCs, 4 DACs, Class-H HP,Class A/B speaker driver,

3x asynchronous serial ports

64 WLCSP65 FBGA

Digital Processing

Volume, Mute, Limiter

Level Shif ters

Control Port

LDO

Auxiliary Serial Port

Audio Serial Port

Voice Serial Port

MCLK1

VL VD_FILT VA

MCLK2

Control Port

Auxiliary Serial Port

Audio Serial Port

Voice Serial Port

Digital MIC Interface

Stereo Multi-bit ΔΣ ADC

Volume, Mute, Limiter

ASRC

ASRC

ASRC

ASRC

ASRC

ASRC

SDIN

MCLK

VD_FILT

VA

MCLK

MCLK

MCLK

+10 or +20 dB

+10 or +20 dB

B

A

VP

B

VP

VA

–VCP_FILT

–VCP_FILT

+VCP_FILT

+VCP_FILT

Headphone Outputs

Pseudo Diff. Input

Pseudo Diff. Input

Line Input (Left )

Line Input (Right )

Pseudo Diff. Input

Pseudo Diff. Input

Psuedo Diff. Input

MIC 1

MIC 2

VP

Ear Speaker Output

Speakerphone Output (Left )

Speakerphone Line Output (Right )

+ –

+ –

+ –

Line Outputs

–6 to +12 dB, 0.5 dB steps

SDIN

SDIN

SDOUT

SDOUT

SDOUT

Digital Mixer

+

MIC/Line Input Path

Auxiliary Serial Port

Audio Serial Port

Voice Serial Port

VCP +VCP_FILT –VCP_FILT

+ VCP_FILT

– VCP_FILTInverting

Step-Down

Decimator, DC Highpass Filter, Noise Gate, ALC, Volume, Mute,

Swap/Mono

Digital MIC Interface

VP

MIC2_SDETMIC 2 BiasMIC 1 Bias

MIC Bias MIC Bias Short Detect

Stereo Multi-bit ΔΣ DAC

Stereo Multi-bit ΔΣ DAC