Design of 30 A Load Current and 93% Peak Efficiency for Active Clamping Forward Converter With Complete Protection

A chip-level design of 30 A load current and 93% peak efficiency for active clamping forward (ACF) converter is presented in this paper to improve the system performance and compactness for all load range and different input voltages. The topology of the low side ACF and self-driven synchronous rectification is adapted to low output voltage and large load current applications. A homologous IC controller with proposed technique of adaptive maximum duty cycle, slope compensation, and optional driver logic is designed. The IC controller is turned into different working states to cooperate different states of the system and functions for complete protection of overcurrent protection, over temperature protection, under voltage lockout, and soft shutdown. The controller chip is fabricated in 0.18 μm BCD process. The experiment results show that 30 A full load current with a compact volume of 39 cm³ and complete protection has been realized. The overshoot and undershoot of transient response are less than 200 mV at 5 A–25 A within 120 μs and the peak efficiency of 93.0% is achieved.