High-frequency Isolation Drive Circuit of Exciting Source for Electromagnetic Ultrasonic Phased Array

In order to further improve the work efficiency of exciting source for electromagnetic ultrasonic phased array, a method of gate drive circuit design of high frequency isolation for exciting source of electromagnetic ultrasonic phased array was presented in this paper based on half bridge topology structure. Through analyzing the process of turn-on and turn-off loss of MOSFET based on the simplified model structure of MOSFET, satisfied conditions of drive circuit with high frequency isolation were put forward and the reference potential was converted by using fiber optic components isolated pulse signal and DC-DC power supply. The high frequency “floating gate” problem of drive circuit was solved effectively, and the dead-time adjustable circuit was designed by combining the RC differential circuit with Schmitt inverter. The experimental results show that the design of drive circuit can output drive signal in which the frequency is 1.1MHz, the dead-time is 0.32μs, the voltage amplitude is 18.8V, and the duty ratio is 26%. The drive circuit reduces power loss of power switch tube effectively in the practical application of driving MOSFET.