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Low-power DAC features control write sequencer

Wolfson Microelectronics has launched the WM8910, a low-power DAC designed to extend playback time in portable audio applications, such as media players, multimedia phones and hand-held gaming systems. The device delivers high performance audio and reduces power consumption in a slim, low profile form factor. The device features a control write sequencer to ensure ease of system design, and a ground-referenced headphone amplifier to improve ‘pop and click’ performance and reduce external component count, allowing consumer electronics designers to develop differentiated end products at a reduced cost. The DAC features SmartDAC technology, a low power DAC capacitor switching architecture, which enables DAC to headphone power consumption of less than 4.5mW. It also features Class W amplifier technology, an evolution of class G, which includes an adaptive dual drive charge pump and DC servo circuit architecture.

The Class W headphone amplifier technology tracks the actual music signal level and uses an adaptive dual drive charge pump to optimise power dissipation and eliminate the need for large DC blocking headphone capacitors, saving PCB space and the audio subsystem BOM (bill of materials). Audio performance is enhanced by integrating SilentSwitch technology, which extends its ‘pop and click’ suppression capability by incorporating advanced clamp and sequencer circuitry. This feature reduces unwanted noise at the headphone amplifier output during power-up and mute/un-mute by clamping the output to ground. Using an integrated sequencer with programmable delay times to power-up and power-down parts of the device reduces ‘pops and clicks’. The device provides the core for a distributed low power audio subsystem and offers the system designer the option to use the new digital microphones through an integrated digital microphone interface. Analogue line inputs are supported, with bypass paths to the class W headphone and line output also included.