关键词: 半桥电路, 欠压锁定, 比较器, 毛刺检测

Abstract: A high-reliable undervoltage lockout circuit is designed for GaN gate driver chips, which can accurately respond and output protection signal to ensure circuit safety. The undervoltage lockout circuit uses a fast response differential comparator circuit and a resistive voltage divider for sampling to avoid circuit instability caused by switching noise in the feedback loop. A power supply burr detection circuit is added to the undervoltage lockout circuit to ensure the generation of a stable and reliable undervoltage lockout signal. The circuit is designed based on the CSMC 0.18 μm BCD process. The simulation results show that the threshold voltage is 7.3 V when the supply voltage rises and 5.8 V when it falls, with a hysteresis of 1.5 V, avoiding the circuit from repeatedly turning on and off near the threshold voltage.

Key words: half-bridge circuit, undervoltage lockout, comparator, burr detection