Codec with Headphone Driver
The WM8731 is a low power stereo codec with an integrated headphone driver. Stereo line and mono microphone level audio inputs are provided, along with a mute function, programmable line level volume control and a bias voltage output suitable for an electric type microphone. Digital audio input word lengths from 16-32 bits and sampling rates from 8 kHz to 96 kHz are supported. Stereo audio outputs are buffered for driving headphones from a programmable volume control, line level outputs are also provided along with anti-thump mute and power up/down circuitry. The device is controlled via a 2 or 3 wire serial interface. The interface provides access to all features including volume controls, mutes, de-emphasis and extensive power management facilities.
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Technologies
Signal Chain Position
Features
- Stereo audio codec with integrated headphone driver (50㎽ on 16Ω @ 3.3V)
- 1.42 – 3.6 V digital supply
- 2.7 – 3.6 V analog supply (standard)
- 1.8 – 3.6 V analog supply (’L’ version)
- Playback mode power consumption < 18㎽
- 100 dB SNR (‘A’ weighted @ 48kHz) DAC
- 90 dB SNR (‘A’ weighted @ 48kHz) ADC
- Sampling frequency: 8 – 96 kHz
- Main or secondary clocking mode
- USB clocking mode can generate all common MP3 sample rates (incl. 441.kHz) directly from USB clock
- Output volume and mute controls
- Microphone input and electret bias with side tone mixer
- Selectable ADC high pass filter
- 2 or three-wire MPU serial control interface
- Programmable audio data interface modes
- 28-Pin SSOP package
Parametric Specifications
| DACs | 2 |
| ADCs | 2 |
| DAC THD+N (dB) | -84 |
| ADC THD+N (dB) | -76 |
| Sample Rate (kHz) | 96 |
| Analog Power Supply (V) | 2.7-3.6 |
| Power Consumption (mW) | 12-22 |
| Package | 28 QFN |
