Compares with Active Clamp Flyback (ACF) topology, Asymmetric Half Bridge (AHB) Flyback with the characteristic of higher duty cycle and lower voltage stress provides higher efficiency and lower cost. Compares with LLC, AHB which supports wider output voltage capability, has become popular for >100W power design, especially in USB PD application. But, there are some tricks we need to be concerned in real design, such as the position of resonant capacitor and the startup surge current. Asymmetric GaN devices for the AHB design shows excellent efficiency which optimize the cost and performance.
