用于GaN半桥驱动的高可靠欠压锁定电路

High-Reliable Undervoltage Lockout Circuit for GaN Half-Bridge Driver

设计了一种用于GaN栅驱动芯片的高可靠欠压锁定电路,该电路能精确响应并输出保护信号以确保电路安全。欠压锁定采用快速响应的差分比较器电路与电阻分压采样,避免了反馈回路开关噪声引起的电路不稳定问题。在欠压锁定电路中加入电源毛刺检测电路以确保产生稳定可靠的欠压锁定信号。基于CSMC 0.18μm BCD工艺,完成了电路设计。仿真结果表明,供电电压上升时阈值电压为7.3 V、下降时阈值电压为5.8 V,迟滞量为1.5 V,避免了电路在阈值电压附近反复开启与关断。

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 0.18μm 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.