WM8740
w
24-bit, High Performance 192kHz Stereo DAC
DESCRIPTION
FEATURES
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120dB SNR (‘A’ weighted mono @48kHz), THD+N: -104dB
@ FS
117dB SNR (‘A’ weighted stereo @48kHz), THD+N: -104dB
@ FS
Sampling frequency: 8kHz to 192kHz
Selectable digital filter roll-off
Optional interface to industry standard external filters
Differential mono mode needing no glue logic
Input data word: 16 to 24-bit
The WM8740 is a very high performance stereo DAC
designed for audio applications such as CD, DVD, home
theatre systems, set top boxes and digital TV. The WM8740
supports data input word lengths from 16 to 24-bits and
sampling rates up to 192kHz. The WM8740 consists of a
serial interface port, digital interpolation filter, multi-bit sigma
delta modulator and stereo DAC in a small 28-pin SSOP
package. The WM8740 also includes a digitally controllable
mute and attenuator function on each channel.
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Hardware or SPI compatible serial port control modes:
The internal digital filter has two selectable roll-off
characteristics. A sharp or slow roll-off can be selected
dependent on application requirements. Additionally, the
internal digital filter can be by-passed and the WM8740
used with an external digital filter.
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Hardware mode: mute, de-emphasis, audio format
control
Serial mode: mute, de-emphasis, attenuation (256
steps), phase reversal
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Fully differential voltage outputs
The WM8740 supports two connection schemes for audio
DAC control. The SPI-compatible serial control port
provides access to a wide range of features including on-
chip mute, attenuation and phase reversal. A hardware
controllable interface is also available.
APPLICATIONS
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CD, DVD audio
Home theatre systems
Professional audio systems
BLOCK DIAGRAM
W
WM8740
CONTROL INTERFACE
VMIDR
SIGMA
RIGHT
LOW
PASS
FILTER
VOUTRP
VOUTRN
SCLK
MUX
MUX
DELTA
MUTE/
ATTEN
DAC
MODULATOR
BCKIN
SERIAL
INTERFACE
DIGITAL
FILTERS
LRCIN
DIN
SIGMA
LEFT
LOW
PASS
FILTER
VOUTLP
VOUTLN
DELTA
MODULATOR
DAC
MUTE/
ATTEN
VMIDL
WOLFSON MICROELECTRONICS plc
Production Data, April 2004, Rev 4.0
Copyright 2004 Wolfson Microelectronics plc
w :: www.wolfsonmicro.com