Stereo ADC with Microphone Preamp

The WM8737 is a low power stereo audio ADC designed specifically for portable applications such as minidisc and memory audio / voice recorders. The device offers three sets of stereo inputs, which can be configured for line-level signals, for internal or table-top microphones, or for DC measurement (battery monitor). A programmable gain amplifier can be used for automatic level control (ALC) with user programmable hold, attack and decay times. The device also has a selectable high pass filter to remove residual DC offsets. If the signal source is mono, the WM8737 can run in mono mode, saving power. It can also mix two channels to mono, either in the analog or the digital domain. Main or secondary mode clocking schemes are offered. Stereo 24-bit multi-bit Delta Sigma ADCs are used with digital audio output word lengths from 16-32 bits, and sampling rates from 8 kHz to 96 kHz supported. The device is controlled via a 2 or 3 wire serial interface. The interface provides access to all features including gain controls, analog or digital mono mixing, and power management facilities. The device is supplied in a leadless 5x5mm QFN package.



  • Complete stereo / mono microphone interface
  • Programmable microphone preamp;
  • Automatic level control;
  • Low-noise microphone bias voltage
  • Configurable power / performance low power mode
  • 8.5mW at AVDD = 1.8V (stereo, mic preamps off)
  • 20mW at AVDD = 3.3V (stereo, mic preamps off)
  • Low supply voltages
    • Analog 1.8V to 3.6V
    • Digital core: 1.42V to 3.6V
  • Digital I/O: 1.8V to 3.6V
  • 256fs / 384fs or USB main clock rates: 12MHz, 24MHz
  • Audio sample rates: 8, 11.025, 12, 16, 22.05, 24, 32, 44.1, 48, 88.2, 96 kHz generated internally from main clock

Parametric Specifications

Channels (Inputs) 2 (6; 3 stereo)
Resolution (bits) 24
Dynamic Range (dB) 97
THD+N (dB) -84
Sample Rate (kHz) 16-96
Analog Inputs/Outputs Single-ended
Analog Power Supply (V) 1.8-3.6
Digital Power Supply (V) 1.42-3.6
Logic Power Supply (V) 1.8-3.6
Operational Power Consumption (mW) 1.4-23.5
Package 32 QFN

Software and Tools

Device Pack for WM8737EV1M

Oct 1, 2004, v1.0 : 1705 Kb


Comprehensive Solutions