Circuit utilization characteristics of MOS-controlled thyristors

The purpose of this paper is to provide an insight into the present state of MOS-controlled thyristor (MCT) development as reflected in measured device terminal characteristics. User-oriented information regarding MCT circuit utilization is presented by focusing on the measured characteristics of a particular batch of MCTs (80 A, 500 V) fabricated in 1988. Measurements confirm the appealingly low forward voltage drop of the MCTs (1.1 V at 200 A/cm/sup 2/, 1500 degrees C). To increase current handling capabilities, eight matched devices have been paralleled to switch 600 A at 275 V (peak), representing a modest 6% device current derating. Measured MCT turn on is faster than turn off, which is dominated by internal charge recombination characteristics. Safe operating area and di/dt limits of the tested MCTs are discussed. Comparison with insulated-gate bipolar transistors (IGBTs) indicates that MCTs offer clear advantages for minimizing on-state conduction losses (approximately 3:1 at 150 degrees C), whereas switching times of new MCTs are as low as those of comparable IGBTs.<
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