A Variable Resistance Thyristor-Type Switch Modeling Technique

An accurate model for simulating the transient turn-ON performance of thyristor-type switches is desirable for the development of solid-state pulse generators. The existing thyristor models are not suitable since they are either impractical to implement in an SPICE simulator, do not accurately model transient turn-ON performance, or are dependent on external circuit parameters that may not be known during the design phase, such as the load and discharge capacitance. An empirical model is developed and presented for Silicon Power's CCS SC 14N40 thyristor. The process of model determination is detailed, and waveforms obtained from the experiment and an SPICE circuit simulation that implements the thyristor model are discussed.

I. Introduction

Traditional pulse generators have achieved high-current and high-voltage switching by the utilization of spark discharges as switches. These switches require more frequent maintenance, possess shorter lifespans, and can introduce more jitter into a system compared with solid-state semiconductor switches. Recent developments in semiconductor design and fabrication [1] have led to silicon devices, such as Silicon Power’s CCS-SC-14N40 thyristor, which features 4-kV voltage hold off and can switch current up to 14 kA for single pulses and 10 kA for repetitive pulses [2].