108/102 dB Stereo Codec

The WM8778 is a stereo audio codec with a multi-bit Delta Sigma A/D converter featuring programmable gain with automatic level control. A stereo multi-bit Delta Sigma D/A converter is used with digital audio input word lengths from 16-32 bits and sampling rates from 32 kHz to 192 kHz. A multiplexor after the DAC allows the selection of either an external analog input or DAC playback into the line outputs. The IC supports fully independent sample rates for both the ADC and DAC, and the audio data interface supports I²S, left justified, right justified and DSP formats. The device is controlled in software via a two- or three-wire serial interface which provides access to all features including volume controls, mutes and de-emphasis facilities. It can also be controlled in hardware which gives access to the most commonly used features. Control interface selection is done via the MODE pin (tri-level).

Technology

Mono/Stereo Codecs

Features

  • Audio performance
  • 108 dB SNR (’A’ weighted @ 48 kHz) DAC
  • 102 dB SNR (’A’ weighted @ 48 kHz) ADC
  • DAC sampling frequency: 32 kHz - 192 kHz
  • ADC sampling frequency: 32 kHz - 96 kHz
  • Stereo ADC input analog gain adjust from +24 dB to -21 dB in 0.5 dB steps
  • ADC digital gain from -21.5 dB to -103 dB in 0.5 dB steps
  • Programmable automatic level control (ALC) or limiter on ADC input.
  • Stereo DAC with analog line outputs.
  • Three-wire SPI compatible or two-wire serial control interface
  • Hardware control mode
  • Master or slave clocking mode
  • Programmable audio data interface modes
  • I²S, left, right justified or DSP
  • 16/20/24/32 bit word lengths
  • Analog bypass path feature
  • 2.7V to 5.5V analog, 2.7V to 3.6V digital supply operation

Parametric Specifications

Channels In 2
Channels Out 2
DAC THD+N (dB) -97
ADC THD+N (dB) -95
Analog Power Supply (V) 2.7-5.5
Supply Current (µA) 2.7-3.6
Package 28 SSOP

Technical Documents

WM8778 Product Datasheet

Jul 1, 2008, v4.2 : 600 Kb

WM8778-EV1B Evaluation Board User Handbook

Feb 1, 2004, v1.1 : 1500 Kb

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