EPC eGaN FETS Deliver Professional Quality Sound with 96% Efficiency

Efficient Power Conversion Corporation (EPC) introduces the EPC9106, a reference design for a 150 W, 8 Ω Class D audio amplifier. This demonstration board uses a Bridge-Tied-Load (BTL) design, composed of four ground-referenced half-bridge output stages, which allows scalability and expandability of the design. All elements that can impact the sonic performance of Class D Audio systems are minimized or eliminated in an eGaN FET-based system.

The EPC9106 features the EPC2016 eGaN FET in conjunction with the LM5113 100 V half-bridge gate driver from Texas Instruments. This board demonstrates that high quality sound can be achieved in a small size due to the performance capabilities of high frequency switching eGaN FETs when coupled with this dedicated eGaN driver. With this high efficiency, the EPC9106 design allows for the complete removal of any heat sink requirement, which also reduces the potential contribution to radiated EMI/EMC emissions.

The power block of the EPC9106 including eGaN FETs, driver, inductor and input/output caps is an ultra-compact 2.1 mm x 1.6 mm layout – about the size of a dime! Despite its small size, the EPC9106 reference design achieves 96% efficiency at 150 W, 8 ohms, and 92% efficiency at 250 W, 4 ohms.

Audio performance for the EPC9106 demonstration board reference design includes: THD+N 0.003% for 8 Ohms, 1kHz, 5W; THD+N 0.005% for 8 Ohms, 1kHz, 15W; THD+N 0.006% for 8 Ohms, 1kHz, 50W; THD+N 0.03% for 8 Ohms, 1 kHz, Full Power; THD+N is less than 0.03% for 8 Ohms, 20Hz to 20kHz, -9 dB; Frequency response +/- 0.5dB, 8 Ohms from 20Hz to 20 kHz; SNR/DNR is 107.8 dB (unweighted) and 110 dB (A-weighted); the continuous power rating is 150W(rms) at 8 Ohms and 250W(rms) at 4 Ohms.