Static induction transistor

The static induction transistor (SIT) is a type of field-effect transistor (FET) capable of high-speed and high-power operation, with low distortion and low noise.^[1] It is a vertical structure device with short multichannel. The device was originally known as a VFET, with V being short for vertical.^[2] Being a vertical device, the SIT structure offers advantages in obtaining higher breakdown voltages than a conventional FET. For the SIT, the breakdown voltage is not limited by the surface breakdown between gate and drain, allowing it to operate at a very high current and voltage. The SIT has a current-voltage characteristic similar to a vacuum tube triode and it was therefore used in high-end audio products, including power amplifiers from Sony in the second half of the 1970s and Yamaha from 1973-1980. The Sony n-channel SIT had the model number 2SK82 with its p-channel complement named 2SJ28.^[2]

Characteristics

A SIT has:

• short channel length
• low gate series resistance
• low gate-source capacitance
• small thermal resistance
• low noise
• low distortion
• high audio frequency power capability
• short turn-on and turn-off time, typically 0.25 μs

History

The SIT was invented by Japanese engineers Jun-ichi Nishizawa and Y. Watanabe in 1950.^[3]

See also

• SIT-based Audio devices
• Static induction thyristor
• JFET

References

1. Nishizawa, Jun-ichi (December 15, 1974). "Field-effect transistor versus analog transistor (static induction transistor)". IEEE Transactions on Electron Devices. 22 (4): 185–197. doi:10.1109/T-ED.1975.18103. S2CID 37015648.
2. Pass, Nelson (2013). "The Sony VFET Amplifier 40 Year Commemorative" (PDF). First Watt. Retrieved August 17, 2022.
3. F. Patrick McCluskey; Thomas Podlesak; Richard Grzybowski, eds. (1996). High Temperature Electronics. CRC Press. p. 82. ISBN 0-8493-9623-9.