US3829709A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Supply reversal protecton circuit
Assignee: MICRO COMPONENTS CORP
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Filing: 1973-08-31
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Granted: 1974-08-13
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Expires: 1993-08-31
Abstract
Abstract A battery powered monolithic integrated circuit is described protected against accidental reversal of the battery in its holder. The protection is obtained by including a PNP lateral transistor in the circuit, connecting the emitter-base of the protection transistor in series with the collector of an NPN transistor, and connecting the protection transistor collector to the N pocket of a resistor included in the circuit.
Inventors
- 👤 R Maigret
- 👤 G King
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 18:43
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/52; H02; H02H; H02H11/00; H02H11/002; H10; H10D; H10D89/00; H10D89/211; H10D89/311; H10D89/60
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
180 words
A monolithic integrated circuit comprising a semiconductive body having a P-type substrate and plural N-type surface pockets isolated from each other by P-N junctions, at least one NPN transistor having emitter, base and collector incorporated in a first one of said N pockets, at least one P resistor having two terminals incorporated into a second one of said N pockets, positive and negative terminals on the body for direct connection to a D.C. supply source, and means for protecting said circuit against accidental reversal of the supply source, said protection means comprising a PNP transistor having emitter, base and collector incorporated into a third one of said N pockets, means connecting the PNP emitter and base in series between the NPN collector and the positive supply terminal, and means connecting the PNP collector to said second N pocket housing the P resistor said means connecting the PNP emitter and base being separate from said means connecting the PNP collector so that the collector of said PNP can assume a positive potential with respect to said base of said PNP transistor.
Claim 2
Dependent Claim
180 words
A monolithic integrated circuit comprising a semiconductive body having a P-type substrate and plural N-type surface pockets isolated from each other by P-N junctions, at least one NPN transistor having emitter, base and collector incorporated in a first one of said N pockets, at least one P resistor having two terminals incorporated into a second one of said N pockets, positive and negative terminals on the body for direct connection to a D.C. supply source, and means for protecting said circuit against accidental reversal of the supply source, said protection means comprising a PNP transistor having emitter, base and collector incorporated into a third one of said N pockets, means connecting the PNP emitter and base in series between the NPN collector and the positive supply terminal, and means connecting the PNP collector to said second N pocket housing the P resistor said means connecting the PNP emitter and base being separate from said means connecting the PNP collector so that the collector of said PNP can assume a positive potential with respect to said base of said PNP transistor.
Claim 3
Dependent Claim
17 words
A monolithic integrated circuit as claimed in claim 1 wherein the protection transistor is operated in saturation.
Claim 4
Dependent Claim
17 words
A monolithic integrated circuit as claimed in claim 2 wherein the protection transistor is a lateral transistor.
Claim 5
Dependent Claim
67 words
A monolithic integrated circuit as claimed in claim 3 wherein the circuit further comprises at least second and third NPN transistors, and at least a second PNP protection transistor, means connecting the emitter-base of the second protection transistor in series between the collector of the second NPN transistor and the positive terminal, and means connecting the collector of the second protection transistor to the third NPN transistor.
Claim 6
Dependent Claim
36 words
A monolithic integrated circuit as claimed in claim 2 wherein means aree provided connecting the P substrate to the negative terminal, and means are provided connecting a terminal of the P resistor to the positive terminal.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-12 | 1978-02-11 | 1978-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-12 | 1982-02-11 | 1982-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-12 | 1986-02-11 | 1986-08-13 | $7700.00 | Window Closed / Lapsed |