Battery life extender

Wolfson Microelectronics has developed SmartDAC, class W amplifier and SilentSwitch technologies to coincide with the launch of the company’s WM8903 CODEC.

When combined, the devices deliver high-performance audio and power consumption, enabling portable device designers to extend battery life.

The DAC capacitor switching drives down the inherent DAC power consumption to ultra-low levels. High PSRR means audio performance is maintained even when powered by noisy switchmode power supplies.

This eliminates the need for a dedicated audio supply allowing a smaller PCB footprint. It also includes a capability for programmable ‘performance vs power’ profiles, where fine grain control of power and audio performance gives the system designer flexibility in meeting demanding power budgets.

The class W amplifier contains an adaptive dual drive charge pump and DC servo architecture and revised capless output drivers.

Designers no longer have to compromise on power consumption, board space or audio quality when using a ground referenced output driver.

This forecasts and optimises amplifier efficiency for ultra-low performance consumption in headphone playback mode based on music content signal levels. ‘Pop and click’ suppression functionality has been enhanced with clamp and sequencer technology. Unwanted noise at the headphone amplifier output is reduced during power-up and power-down by clamping circuitry that holds the headphone output to ground during power up.

The sequencer technology integrated into SilentSwitch enables further advances in ‘pop and click’ suppression during power up/power down. With the integrated register write sequencer, the audio path set-up can be preloaded and executed by the control sequencer with programmable delay times to reduce common ‘pops and clicks’.