Analog Ultra-High Speed Thyristor Design Based on Baker Anti-Saturation Circuit

Abstract

The turn-on time of ordinary thyristors is affected by the distribution parameters and the positive feedback process, and the turn-on time is longer. At the same time, due to the saturation of the internal transistors, the carriers in the three conductive regions accumulate, which results in a long carrier recombination time during turn-off, so the thyristor turn-off time is also very long. In order to solve the problem of slow speed of common thyristor switch, this paper designs an analog ultra-high-speed thyristor with thyristor characteristics. The analog ultra-high-speed thyristor is composed of fully discrete devices, using symmetric Baker anti-saturation clamp. The circuit clamps the tube voltage drop of both transistors to about 1.4V, and the transistor does not enter saturation, which greatly increases the switching time. The measured results show that the analog ultra-high-speed thyristor has an on-time of less than 30 ns and a turn-off time of less than 50 ns. The switching speed is about two orders of magnitude higher than that of the high-frequency thyristor, and provides an idea for the design of high speed power devices and the tube drop clamp of transistors.