POY7.JAN–Harris Semiconductor–wy
MOS-controlled thyristor excels in high-power switching
The MOS-controlled thyristor (MCT), a new type of semiconductor power switching device from Harris Semiconductor, boasts a current rating greater than twice that of an IGBT, power MOSFET, or bipolar Darlington transistor of the same die size. Furthermore, the MCT exhibits a much lower forward-voltage drop (and conduction loss) than these other devices.
The only other semiconductor power switch that even approaches the MCT in conduction efficiency is the GTO (gate turn-off silicon-controlled rectifier). But the GTO requires orders of magnitude more gate-control power than the MCT. Consequently, today's demands for highly energy efficient devices should make the MCT particularly attractive to designers of power delivery and power control applications like power supplies, appliances, automobile, aircraft, and power utilities.
An MCT consists essentially of an SCR that employs on-chip MOS transistors as gating devices, one transistor to turn the device on and the other to turn it off. Two devices are now available in Harris' MCT family. The first, the P-type MCTA75P60E1, has a peak off-state blocking voltage rating of 600 V and is rated at 75 A continuous current at 90 degreesC case temperature. Forward-voltage drop is only 1.3 V. The second device, the MCTA65P100F1 is rated at 1,000 V peak off-state blocking at 65 A continuous current and 1.4 V forward drop. Both devices provide a current rating at least 2.3 times the rating of IGBTs, MOSFETs, and bipolar Darlingtons of the same die size.
Ruggedness is a hallmark of MCT devices. Like all thyristors, they can operate at high peak currents and withstand both large surge currents and a high rate of change of on-state current (di/dt capability). For example, non-repetitive peak surge current is 2,000 A and di/dt is 2,000 A/μs. Furthermore, unlike traditional SCRs, MCTs have high resistance to false triggering on fast rise-time pulses applied between anode and cathode terminals because of the off-FET element–the MCT dv/dt rating is 10,000 V/μs.
MCTs are available in TO-247 (five-lead) and MO-93 (five-lead TO-218) plastic packages. (From $24 ea/1,000–stock.)
Harris Semiconductor
Melbourne, FL
Information 800-4-HARRIS, ext. 7049
CAPTION:
The MOS-controlled thyristor (MCT), an SCR gated on and off by integrated MOS transistors, has a much smaller forward-voltage drop than IGBTs, MOSFETs, and bipolar Darlingtons of the same die size.
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