Semiconductor device protection circuit

Electricity: electrical systems and devices – Safety and protection of systems and devices – Circuit interruption by thermal sensing

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

361 18, 323907, H02H 504

Patent

active

051192659

ABSTRACT:
FET protection circuit (10; 100) senses the temperature of a FET (11) and, via a control circuit (24), increases FET conduction in response to sensed FET temperature exceeding a high temperature threshold (160.degree. C.) close to the maximum rated junction temperature (175.degree. C.) of the FET. This allows the FET to survive excessive drain-to-source voltages which occur during load dump conditions even when load dump is sensed by a zener diode (26) which initially turns on the FET. During load dump after a zener diode (26) turns on the FET, in response to sensing excessive FET temperature the FET is turned in harder so as to reduce the drain-to-source voltage (V.sub.DS) and minimize power dissipation during load dump thereby protecting the FET. Normal overcurrent and maximum temperture turn off circuitry (44, 33, 60-63) is effectively overridden by high temperature threshold turn-on circuitry (50). Preferably, a majority of the control circuit (24) is provided on an integrated circuit, but an external resistor (31) allows effective adjustment of two temperature thresholds (150.degree. C., 160.degree. C.) above which control signals provided to the FET will be modified.

REFERENCES:
patent: 4516865 (1985-05-01), Hideo
patent: 4667516 (1987-05-01), Schulz
patent: 4896245 (1990-01-01), Qualich
patent: 4924194 (1990-05-01), Opas
patent: 4937697 (1990-06-01), Edwards et al.
"High Side Driver FET Load-Dump Protection", by John Qualich, Motorola Technical Developments vol. 9, Aug. 1989, pp. 62-63.
"Built-in Protection Makes TEMPFET Resistant to Catastrophic Failures" by Miro Glogolja, Power Conversion & Intelligent Motion, Mar. 1989 pp. 19-23.
"Self-Thermal Protection Power MOSFETS", by Tsazaki, Y.; Yamauka, M. and Kawamuto, K.; IEEE Power Electronic Specialists Conference, Paper No. 880411, pp. 41-45 or 87CH2459-6, pp. 31-36.
"Prior Low Side FET Switch",m (Sketch) Feb. 21, 1990.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Semiconductor device protection circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Semiconductor device protection circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Semiconductor device protection circuit will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2234125

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.