Ultra Low Power Audio Subsystem

The WM9094 is a low power audio subsystem that combines a headphone driver with a Class AB/Class D earpiece/speaker driver. The Class D speaker driver supports 650 mW output power at 3.6 V at 1%THD. A dual mode charge pump architecture provides ground referenced headphone outputs removing the requirement for external coupling capacitors. Class G technology increases efficiency and extends playback time by optimizing the headphone driver supply voltages according to the volume control. Mixers allow highly flexible routing to the outputs. Separate mixer and volume controls are provided for each headphone and speaker driver. Automatic Gain Control limits the speaker output signal in order to prevent clipping.


Audio Amplifiers


  • Differential and single ended analog input configurations
  • Start up time <50 ms
  • Shutdown current < 1 uA
  • Available ‘voice bypass’ for low power voice applications
  • Two-wire I²C interface
  • Integrated oscillator generates all clock frequencies
  • Pop and click suppression

Parametric Specifications

Input Type Analog
Channels Speaker Driver;
1 x Mono Class D;
1 x Stereo Class AB;
Headphone Driver
Output Power (V) 2 W into 4 ohm (speaker);
34 mW into 16 ohm (headphone)
SNR (dB) 92
THD+N @ 1 W (dB) 0.02
Power Supply (V) 2.7-5.5
Supply Current (µA) 1.35-2
Package 20 WLCSP

Technical Documents

WM9094 Product Data Sheet

Mar 1, 2013, v4.0 : 1413 Kb


Comprehensive Solutions