EL SEGUNDO, Calif. — September 2021 — Idle power consumption and overall efficiency were key concerns of innosonix GmBH when designing its latest high-end Maxx Series multi-channel power amplifier. By changing from traditional silicon FETs to EPC’s EPC2059 eGaN FET the company reduced idle loss by 35% and lowered the on resistance to increase the total power efficiency by 5%.

The EPC2059 is a 6.8 mΩ, 170 V enhancement-mode gallium nitride (eGaN) transistor offering superior audio performance for high-end amplifier applications. The low on resistance and low capacitance of the EPC2059 enables high efficiency and lowers open loop impedance for low Transient Intermodulation Distortion (T-IMD). The fast-switching capability and zero reverse recovery charge enable higher output linearity and low cross over distortion for lower Total Harmonic Distortion (THD).

With the current maturity of Class-D audio amplifier architectures, amplifier fidelity and efficiency limitations are primarily at the device level. Silicon MOSFETs have been evolving for almost forty years, and their progress towards a perfect switch has slowed dramatically. There are some fundamental characteristics of MOSFETs that degrade sound quality and efficiency. In 2010, the enhancement mode Gallium nitride (GaN) power FET was introduced by Efficient Power Conversion (EPC), providing a large step towards the perfect switch.

Audio Engineering Society
May 11, 2017
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The quality of sound reproduced by an audio amplifier, measured by critical performance parameters such as THD (Total Harmonic Distortion), damping factor (DF), and T-IMD (Inter-modulation Distortion), is influenced by the characteristics of the switching transistors used. Class-D audio amplifiers typically use power MOSFETs, however, lower conduction losses, faster switching speed, and zero reverse recovery losses provided by enhancement-mode GaN (eGaN) FETs enable a significant increase in the sonic quality, and higher efficiency that can eliminate heatsinks. The result is a system with better sound quality in a smaller form factor that can be built at a lower cost.

EEWeb
By: Alex Lidow
February, 2014