US3670219A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current limiting transistor
Assignee: Motorola Solutions Inc
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Filing: 1970-12-07
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Granted: 1972-06-13
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Expires: 1990-12-07
Abstract
Abstract A transistor which may be fabricated on a chip is disclosed whose beta remains at about a constant value with collector current up to a desired percentage above the maximum rated load value thereof and then falls off very rapidly, whereby the collector current never exceeds a desired value. This is accomplished by providing a resistor using the emitter diffusion, within the base region of the transistor and then passing all of the emitter current through this resistor. At a designable value of current flow, transistor action is locally, enhanced at the remote end of this emitter resistor and the current gain of the transistor is thereby degraded as high level injection conditions are artifically established in this localized region.
Inventors
- 👤 Thomas M Frederiksen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:55
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/60; H10D84/611; H10D84/613; H10D84/615; H10D62/00; H10D62/10; H10D62/13; H10D62/133; H10D62/135
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
124 words
A current limiting transistor, comprising: a. a collector region of a first conductivity type; b. a base region of a second conductivity type, disposed within the collector region; c. at least one emitter region, of the first conductivity type, disposed within the base region and having a contact; and d. an elongated emitter region of the first conductivity type disposed within the base region forming an acTive junction therewith, in combination with the collector comprising a distributive transistor, having a contact at one end thereof electrically connected to the emitter region contact, and having means for external connection at the other end, providing a resistive current path for causing a high level injection at the other end when the current reaches a prescribed level.
Claim 2
Dependent Claim
124 words
A current limiting transistor, comprising: a. a collector region of a first conductivity type; b. a base region of a second conductivity type, disposed within the collector region; c. at least one emitter region, of the first conductivity type, disposed within the base region and having a contact; and d. an elongated emitter region of the first conductivity type disposed within the base region forming an acTive junction therewith, in combination with the collector comprising a distributive transistor, having a contact at one end thereof electrically connected to the emitter region contact, and having means for external connection at the other end, providing a resistive current path for causing a high level injection at the other end when the current reaches a prescribed level.
Claim 3
Dependent Claim
41 words
The transistor of claim 1 further comprising at least one additional emitter region of the first conductivity type, disposed within the base region, and having a contact electrically connected to the emitter region contact and to the elongated emitter region contact.
Claim 4
Dependent Claim
17 words
The transistor of claim 1 wherein the elongated emitter region contact is positioned adjacent the emitter region.
Claim 5
Dependent Claim
17 words
The transistor of claim 2 wherein the elongated emitter region contact is positioned adjacent the emitter region.
References Cited (Backward Citations)
US3358197A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-13 | 1975-12-13 | 1976-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-13 | 1979-12-13 | 1980-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-13 | 1983-12-13 | 1984-06-13 | $7700.00 | Window Closed / Lapsed |