Patent US4730228A successfully refreshed from Google Patents.
US4730228A
Expired / Lapsed
US
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Overtemperature detection of power semiconductor components
Assignee: Siemens AG
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Filing: 1986-07-16
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Granted: 1988-03-08
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Expires: 2006-07-16
Abstract
Abstract The temperature of the power semiconductor component is sensed by a bipolar transistor. The bipolar transistor is in series with a depletion mode MOSFET whose gate and source electrodes are connected together. The drain electrode is also connected to a threshold element. Normally, the FET has low impedance, so that at the input of the threshold element source potential, e.g. ground potential, is present. With current rising as a function of temperature, the current through the FET is limited to a constant, essentially temperature-independent value, and the potential at the input of the threshold element rises steeply. This condition is detected as an overtemperature signal.
Inventors
- 👤 Josef Einzinger
- 👤 Christine Fellinger
- 👤 Ludwig Leipold
- 👤 Jenoe Tihanyi
- 👤 Roland Weber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:59
CPC Classifications
G; G01; G01K; G01K7/00; G01K7/01; G01K3/00; G01K3/005; Y; Y10; Y10S; Y10S323/00; Y10S323/907
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
124 words
In a circuit arrangement for the generation of a signal when a critical temperature in a power semiconductor component is exceeded, said circuit arrangement using semiconductor components with temperature-dependent current/voltage characteristics, the improvement comprising: a bipolar transistor (T 1) in thermal contact with the power semiconductor component and having a temperature dependent leakage current flowing therethrough; a current source connected in series with said bipolar transistor, said current source having a current demand which is greater than said leakage current of said bipolar transistor at a given temperature which is less than said critical temperature; and a threshold element having an input connected to the emitter electrode of said bipolar transistor and an output which provides said signal when said critical temperature is exceeded.
Claim 2
Dependent Claim
124 words
In a circuit arrangement for the generation of a signal when a critical temperature in a power semiconductor component is exceeded, said circuit arrangement using semiconductor components with temperature-dependent current/voltage characteristics, the improvement comprising: a bipolar transistor (T 1) in thermal contact with the power semiconductor component and having a temperature dependent leakage current flowing therethrough; a current source connected in series with said bipolar transistor, said current source having a current demand which is greater than said leakage current of said bipolar transistor at a given temperature which is less than said critical temperature; and a threshold element having an input connected to the emitter electrode of said bipolar transistor and an output which provides said signal when said critical temperature is exceeded.
Claim 3
Dependent Claim
42 words
A circuit arrangement according to claim 1, wherein: said current source is a depletion mode FET, the source and gate electrodes of which are connected to each other and whose drain electrode is connected to the emitter electrode of said bipolar transistor.
Claim 4
Dependent Claim
29 words
A circuit arrangement according to claim 2, wherein: at least one Zener diode is connected between the input terminal of the threshold element and a source of ground potential.
Claim 5
Dependent Claim
27 words
A circuit arrangement according to claim 2 wherein: said bipolar transistor is disposed at least approximately in the center of a surface of said power semiconductor component.
Claim 6
Dependent Claim
19 words
A circuit arrangement according to claim 1, characterized in that the base connection of said bipolar transistor is open.
Claim 7
Dependent Claim
27 words
A circuit arrangement according to claim 5 wherein: said bipolar transistor is disposed at least approximately in the center of a surface of said power semiconductor component.
Claim 8
Dependent Claim
29 words
A circuit arrangement according to claim 1, wherein: at least one Zener diode is connected between the input terminal of the threshold element and a source of ground potential.
Claim 9
Dependent Claim
27 words
A circuit arrangement according to claim 7 wherein: said bipolar transistor is disposed at least approximately in the center of a surface of said power semiconductor component.
Claim 10
Dependent Claim
27 words
A circuit arrangement according to claim 1 wherein: said bipolar transistor is disposed at least approximately in the center of a surface of said power semiconductor component.
Claim 11
Dependent Claim
24 words
A circuit arrangement according to claim 9 wherein: said current source is integrated into said power semiconductor component and is disposed at its edge.
Claim 12
Dependent Claim
24 words
A circuit arrangement according to claim 1 wherein: said current source is integrated into said power semiconductor component and is disposed at its edge.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-08 | 1991-09-07 | 1992-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-08 | 1995-09-07 | 1996-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-08 | 1999-09-07 | 2000-03-08 | $7700.00 | Window Closed / Lapsed |