
Wolfson Microelectronics plc
DESCRIPTION
The WM8711 or WM8711L (WM8711/L) is a low power stereo DAC with an integrated headphone driver. The WM8711/L is designed specifically for portable MP3 audio and speech players. The WM8711/L is also ideal for MD, CD machines and DAT players.
Stereo 24-bit multi-bit sigma delta DACs are used with oversampling digital interpolation filters. Digital audio input word lengths from 16-32 bits and sampling rates from 8KHz to 96KHz 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. The device is available in a small 28- lead SSOP package or the smaller 28-lead QFN (5x5x0.9 mm Body) package.
A USB mode is provided where all audio rates can be derived from a single 12MHz or 24MHz MCLK, saving on the need for a PLL or multiple crystals.
FEATURES
• Audio Performance
- DAC SNR 100dB (‘A’ weighted) at AVDD = 3.3V
- DAC SNR 90dB (‘A’ weighted) at AVDD = 1.8V (WM8711L)
• Low Power Headphone Playback
- Down to 20mW at 3.3V
- Down to 6mW at 1.8V (WM8711L)
- 1.42 – 3.6V Digital Supply Operation
- 2.7 – 3.6 V Analogue Supply Operation
- 1.8 – 3.6 V Analogue Supply Operation (‘L’ Variant)
• DAC Sampling Frequency: 8KHz – 96KHz
• 2 or 3-Wire MPU Serial Control Interface
• Programmable Audio Data Interface Modes
- I2S, Left, Right Justified or DSP
- 16/20/24/32 bit Word Lengths
- Master or Slave Clocking Mode
• Stereo Audio Outputs
• Output Volume and Mute Controls
• Highly Efficient Headphone Driver
• 28-lead SSOP or 28-lead QFN (5x5x0.9 mm) package
APPLICATIONS
• Portable MP3 Players
• CD and Minidisc Players