Switching lots of watts at high speeds

Large power handling solid-state devices are discussed and compared. MOSFETs have an insulated gate structure and require negligible steady-state input gate-drive currents, while successful designs include suppression of the activation of a parasitic npn bipolar transistor between the source and the drain by shortening the emitter. The vertical channel JFET has a high-frequency switching capability, and devices handling up to 200 W at 500 V have been fabricated. Field controlled thyristors can operate at current densities 10 times the MOSFET limits and 2500 V breakdown, 500 A devices have been reported. Increases in power handling capabilities and VLSI of MOSFETs are examined, and prospects for GaAs FETs and new designs for power ICs are reviewed.