用于GaN半桥驱动器的高速电平移位电路

A High Speed Level Shift Circuit for GaN Half-Bridge Driver

设计了一种GaN半桥驱动器高性能电平移位电路,一方面采用短脉冲控制的高速镜像噪声电流与噪声电流相互抵消的方法消除共模噪声,另一方面采用脉冲宽度调制(PWM)控制的正反馈互锁电路,该电路不含RC滤波,用来消除由于工艺偏差造成的差模噪声,以保证输出信号稳定。抗负压电路采用降压电平移位电路实时监测高侧电压浮动状态并反馈回自举充电回路,使充电时间避开负压时间。在0.18μm 85 V BCD工艺下完成设计,工作频率达到5 MHz,上升时间为4.1 ns,下降时间为3.8 ns,满足高频GaN栅驱动应用需求。

A GaN half-bridge driver high-performance level shift circuit was designed.On the one hand, short pulse-controlled high-speed mirror noise current and noise current were used to balance each other to eliminate common mode noise.On the other hand, a pulse width modulation(PWM)-controlled positive feedback interlock circuit without RC filtering was used to eliminate the differential mode noise caused by process deviation, ensuring the stable output signal.The anti-negative voltage circuit adopts a buck level shift circuit to monitor the high-side voltage floating state in real time and feed back to the bootstrap charging circuit so that the charging time can avoid the negative voltage time.The design was completed in 0.18 μm 85 V BCD process with an operating frequency of 5 MHz, a rise time of 4.1 ns and a fall time of 3.8 ns.The design meets the requirements of high frequency GaN gate drive applications.