IGBT/FRED Technology Reduces AC Motor Dead Time Dramatically

Reported to increase useful AC motor speed ranges by reducing dead time by a factor of three with 20% power loss, the company's process technology for insulated gate bipolar transistors (IGBTs) and fast recovery epitaxial diodes (FREDs) promises 70% faster turn-off times than previous generation devices. Using this process, devices are capable of 0.3-µs turn-off times compared to 1.6 µs previously. Speed range is increased by reducing the inverter dead-time and by proportionally expanding the PWM duty cycle and the modulated frequency range. In addition, the new devices's gate characteristics have three times greater noise immunity, and dv/dt induced turn-on current is reduced by a factor of twenty compared to similar devices. Two IGBT/FRED devices, the IRGPSS60B120KD and IRGPSS40B120UD, are available. The IRGPSS60B120KD is for motor drives and operates at frequencies up to 25 kHz; the IRGPSS40B120UD is for UPS, welding and power supply applications and operates at frequencies up to 50 kHz. The price for both devices is $8.32 each/10K. INTERNATIONAL RECTIFIER, El Segundo, CA. (310) 252-7105.