WM8722

Stereo DAC with Integrated Tone Generator and

Line/Variable Level Outputs

Advanced Information, May 2000, Rev 1.5

WOLFSON MICROELECTRONICS LTD

Lutton Court, Bernard Terrace, Edinburgh, EH8 9NX, UK

Tel: +44 (0) 131 667 9386

Fax: +44 (0) 131 667 5176

Email: sales@wolfson.co.uk

http://www.wolfson.co.uk

Advanced Information data sheets contain

preliminary data on new products in the

preproduction phase of development.

Supplementary data will be published at a

later date.

2000 Wolfson Microelectronics Ltd

.

DESCRIPTION

The WM8722 is a high performance stereo DAC designed

for audio applications such as digital TV and set top boxes.

The WM8722 has two stereo analogue outputs, one at line

level and one that includes a digitally controllable mute and

attenuator function. An on-board tone generator can be

routed through the line or variable outputs.

WM8722 supports data input word lengths from 16-24 bits

and sampling rates up to 96kHz. The WM8722 consists of a

serial interface port, digital interpolation filter, multi-bit sigma

delta modulator and stereo DAC in a small 20-pin SSOP

package.

The 3 or 2-wire serial MPU compatible control port provides

access to all features including tone generation, on-chip

mute, attenuation and phase reversal.

The programmable data input port supports glueless

interfaces to popular DSPs, audio decoders and S/PDIF

and AES/EBU receivers.

FEATURES

•

Performance

−

102dB SNR (‘A’ weighted @48kHz)

−

THD+N: -90dB @ F.S.

−

5V or 3V supply operation

−

Sampling frequency: 8kHz – 96kHz

•

3-wire or 2-wire serial MPU compatible interface for

−

Input data word; 16/20/24-Bit

−

Soft mute

−

De-emphasis

−

Volume control

•

On-board tone generator (1Hz – 32kHz, 0.1 – 25.5s)

•

Stereo analogue inputs

•

20-pin SSOP package

APPLICATIONS

•

Digital TV

•

Digital broadcast receivers

•

Set top boxes

BLOCK DIAGRAM

DIN (17)

SERIAL

INPUT

INTERFACE

BCKIN (19)

LRCIN (18)

SCKI (20)

TONE

GENERATOR

MD (3)

MC (2)

LATCH (4)

DIGITAL

ATTENUATOR

AND

FILTERS

MULTI

BIT

∑∆

TONE

DAC

MULTI

BIT

SC

DAC

DIGITAL

ATTENUATOR

AND

FILTERS

MULTI

BIT

∑∆

MULTI

BIT

SC

DAC

(7)

MXINR

MXINL(14)

(13)LINEOUTL

(12) VAROUTL

+6 to -73dB,

1dB Steps

(9) VAROUTR

(8) LINEOUTR

0 TO -46.5dB, 1.5dB

STEPS

(15)

CAP

(11)

AVDD

(10)

AGND

(6)

DGND

+

I2S/SDIF

16,18, 20

OR 24 BITS

BUSY (5)

TCLK (1)

+12 to -34.5dB, 1.5dB Steps

+

+

+

WM8722

0/-6dB

0/-6dB

0/-6dB

MONO ATTENUATION CONTROL

4

L Mix Switches (0-9)

+12 TO -34.5dB, 1.5dB

STEPS

(16)

DVDD

0/-6dB

R Mix Switches (0-9)