An Improved Peak Current Control Method for GaN-based Active-clamped Flyback Converter

In the conventional peak current controlled active-clamped flyback converter, the primary side current sampling resistor R
_s
brings many problems, among which the additional power consumption and instability are the most obvious ones. A new peak current control method without sampling resistor is proposed, which is suitable for both analog control (based on Analog IC or discrete components) and digital control (based on FPGA, ASIC, MCU, DSP, etc.). To exemplify, the FPGA-based digital control method is taken as case study, and the proposed control method is verified by experimental results. In a GaN-based 12V-3A ACF, the average efficiency is improved by upto 2.92% compared to the conventional peak current control methods. In addition, the dynamic response is greatly improved, and analysis is given to explain this improvement.