A high-efficiency hysteresis buck converter using auto selectable frequency-locked techniques

A high-efficiency wide workload hysteresis buck converter using auto selectable frequency-locked techniques is designed with the TSMC 0.18-μm 1P6M process. The proposed buck converter yields fast-response by using hysteresis control. The workload range, power efficiency, and EMI noise problem are improved by auto-selectable frequency and frequency-locked techniques. The selected switching frequency is determined with load current. Simulation results show that this buck converter´s switching frequency is locked at four frequencies for the load current between 10 and 400mA: 250k, 500k, 1M, and 2MHz. Furthermore, it achieves more than 90% power efficiency over 95% of the load range, with a peak efficiency of 96.27%.