IP reduces capacitor requirements in headphone drivers

June 17, 2013 // By Graham Prophet
With BassPower for headphones, Dolphin Integration says that its IP for audio drivers eliminates up to 80% of external capacitor cost.

Sourcing the most appropriate IP can help to reduce the Bill of Material. For portable devices, such as smartphones and tablets, the race to the reduction of device thickness adds constraints on PCB area and package thickness. Dolphin Integration provides audio codecs with its BassPower headphone feature. This innovation, in very low silicon area, enables a significant cost reduction of the bill of materials.

For mastering this application challenge and dealing with TRRS phone connectors (Left/Right output with microphone input) – mandatory in hands-free set applications – Dolphin now provides two different solutions:

- A True-ground headphone driver, the best solution whenever a triple-well option is already used by another part of the SoC: or,

- The BassPower solution, maintaining cost down by using standard CMOS processes. BassPower enables reduction of capacitor value from 220 µF down to 10 µF!

BassPower is also provided with three pre-defined settings (Ultra-linear, Bass Attack preserved, Max volume) for adjusting the BassPower flavour.

The high configurability of bass compensation over frequencies allows support of a large set of application schematics, enabling the user to define the best trade-off between Bill-of-Material and maximum output power delivered to the headphone. Furthermore, BassPower remains the same from one audio source to another whatever the sampling frequency, in contrast to DSP solutions which need to readjust their settings. Consequently, BassPower enables a cost-effective solution for smartphone and tablet applications and preserves the quality of audio experience. It is available on an audio converter portfolio that includes proven 24-bit sigma-delta Audio Codecs from 180 nm to 40 nm available in major foundries, with up to 100 dB of SNR, THD of -80 dB for the line-in to ADC path, and < 8.0 mW of power consumption for DAC playback mode at 2.5V.

Dolphin Integration; www.dolphin.fr/flip/analog/analog_catalogue_audio.php