Efficient Power Conversion Corporation (EPC) introduces the EPC9106, a reference design for a 150 W, 8 ohm 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 eGaNR FET-based system.
According to Dr. Skip Taylor, co-founder and former CTO of Intersil’s D2 Audio, “An eGaN FET power stage provides a precise high-power reproduction of the Class-D PWM signal with extremely high linearity. This high linearity reduces the need for large amounts of feedback, ultimately allowing for the best possible audio quality providing clean, crisp middle and high frequencies and a tight, solid reproduction of the low frequencies.”
The EPC9106 features the EPC2016 eGaN FET in conjunction with the LM5113 eGaN FET 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. 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 and overall system cost.
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. Despite its small size, the EPC9106 reference design achieves 96% efficiency at 150 W, 8 ohms, and 92% efficiency at 250 W, 4 ohms.
