US3654530A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated clamping circuit
Assignee: International Business Machines Corp
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Filing: 1970-06-22
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Granted: 1972-04-04
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Expires: 1990-06-22
Abstract
Abstract An integrated clamping circuit is provided in which the bulk collector resistance of a transistor is coupled to the base contact by a second collector contact to bias the collector-base junction in response to a potential difference between the base and main collector contacts. The level of collector-base junction bias is determined in part by the size of the auxiliary collector contact and its location relative to a heavily doped buried layer in the collector. The biased transistor conducts in a manner so as to clamp the voltage at the output terminal of an associated electrical device for load current above a threshold value.
Inventors
- 👤 Robert H F Lloyd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:54
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/13; H10D62/137; H10D84/00; H10D84/60; H10D84/611; H10D84/613; H10D84/615
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
276 words
A clamping circuit comprising the combination of a pair of terminals, a base element, an emitter element in emitter-base junction forming contact with the base element, a collector element in collector-base junction forming contact with the base element, means coupling one or the pair of terminals to a surface portion of the emItter element, means coupling the other of the pair of terminals to a first surface portion of the collector element, resistor means coupled between the surface portion of the emitter element and a surface portion of the base element and responsive to a potential difference between the pair of terminals to bias the emitter-base junction, and means coupling the surface portion of the base element to a second surface portion of the collector element, that part of the collector element which extends between the second surface portion thereof and the collector-base junction being responsive to a potential difference between the pair of terminals to bias the collectorbase junction, the collector element includes a buried layer of material of relatively high semiconductivity extending from a region adjacent the collector-base junction to regions adjacent the first and second surface portions of the collector element, the means coupling the other of the pair of terminals to a first surface portion of the collector element includes a main collector contact disposed on the first surface portion of the collector element, and the means coupling the surface portion of the base element to a second surface portion of the collector element includes an auxiliary collector contact disposed on the second surface portion of the collector element, said main collector contact being larger in size than said auxiliary collector contact.
Claim 2
Dependent Claim
276 words
A clamping circuit comprising the combination of a pair of terminals, a base element, an emitter element in emitter-base junction forming contact with the base element, a collector element in collector-base junction forming contact with the base element, means coupling one or the pair of terminals to a surface portion of the emItter element, means coupling the other of the pair of terminals to a first surface portion of the collector element, resistor means coupled between the surface portion of the emitter element and a surface portion of the base element and responsive to a potential difference between the pair of terminals to bias the emitter-base junction, and means coupling the surface portion of the base element to a second surface portion of the collector element, that part of the collector element which extends between the second surface portion thereof and the collector-base junction being responsive to a potential difference between the pair of terminals to bias the collectorbase junction, the collector element includes a buried layer of material of relatively high semiconductivity extending from a region adjacent the collector-base junction to regions adjacent the first and second surface portions of the collector element, the means coupling the other of the pair of terminals to a first surface portion of the collector element includes a main collector contact disposed on the first surface portion of the collector element, and the means coupling the surface portion of the base element to a second surface portion of the collector element includes an auxiliary collector contact disposed on the second surface portion of the collector element, said main collector contact being larger in size than said auxiliary collector contact.
Claim 3
Dependent Claim
66 words
A clamping circuit in accordance with claim 1, wherein that portion of the collector element which extends between the buried layer and the auxiliary collector contact defines the major portion of a collector-base junction biasing resistor, and the size of the auxiliary collector contact and the location thereof relative to the buried layer are chosen to provide the collector-base junction biasing resistor with a selected value.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-04 | 1975-10-04 | 1976-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-04 | 1979-10-04 | 1980-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-04 | 1983-10-04 | 1984-04-04 | $7700.00 | Window Closed / Lapsed |