Electrical transmission or interconnection systems – Personnel safety or limit control features – Interlock
Patent
1979-01-22
1981-10-20
Larkins, William D.
Electrical transmission or interconnection systems
Personnel safety or limit control features
Interlock
307253, 307302, 357 13, 357 34, 357 36, H03K 1710, H03K 1764, H01L 2972
Patent
active
042963362
ABSTRACT:
A switching circuit includes a transistor having a base, collector, and emitter terminals, a load device connected to the collector terminal and a supply voltage, and circuitry connected to the base terminal for conducting a turn-off current out of the base terminal. The transistor has an emitter bonding pad which extends from the edge of the emitter region over the collector. A region of the same conductivity type as the base region of the transistor and spaced from the base region is disposed in the collector region and contacts the emitter bonding pad. Charge is drawn out of the base region of the transistor at a rate sufficient to reverse bias the entire emitter-base junction before the collector attains the minimum secondary breakdown voltage level of the transistor. The geometry of the transistor is such that the maximum distance between the base contact region and any point of the emitter is sufficiently small to prevent the degree of constriction of emitter current which will cause the critical electrical field of the collector region to be exceeded. The rate of increasing the voltage of the collector beyond the secondary breakdown level of the transistor leading to base width modulation does not cause forward biasing of any portion of the emitter-base junction after the collector voltage exceeds the secondary breakdown voltage level of the transistor.
REFERENCES:
patent: 3271201 (1966-09-01), Pomerantz
patent: 3358197 (1967-12-01), Scarlett
patent: 3400310 (1968-09-01), Dorendorf et al.
patent: 3418495 (1968-12-01), Bose
patent: 3444443 (1969-05-01), Moroshima
patent: 3546492 (1970-12-01), Barchok
patent: 3614553 (1971-10-01), Franklin et al.
patent: 3628047 (1971-12-01), Cronin et al.
patent: 3736495 (1973-05-01), Calkin et al.
patent: 3936863 (1976-02-01), Ohmstead
patent: 4123670 (1978-10-01), Pollmeier
patent: 4157561 (1979-06-01), Nawata et al.
patent: 4239989 (1980-12-01), Brajder
RCA Power Transistors, RCA Technical Series PM-81 (RCA, Somerville, N. J., 1971), pp. 38-43 (Exr's personal copy).
Beatty et al., "Second Breakdown in Power Transistors . . . ", IEEE Transactions on Electron Devices, vol. ED-23, No. 8, Aug. 1976, pp. 851-857.
Gillett, "Power Transistor Having Increased Reverse Bias Safe Operating Area", IBM Technical Disclosure Bulletin, vol. 16, No. 11, Apr. 1974, p. 3642, (357-36).
Wang, "Power Transistor with Reverse-Biased Second Breakdown Capability", IBM Technical Disclosure Bulletin, vol. 19, No. 2, Jul. 1976, pp. 551-552 (357-34).
General Semiconductor Co., Inc.
Larkins William D.
LandOfFree
Switching circuit and method for avoiding secondary breakdown does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Switching circuit and method for avoiding secondary breakdown, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Switching circuit and method for avoiding secondary breakdown will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1493196