Patent EP0425035A2 successfully refreshed from Google Patents.
EP0425035A2
Expired / Lapsed
EP
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Overload protection drive circuit for a power transistor
Assignee: Koninklijke Philips NV
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Filing: 1990-10-19
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Granted: —
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Expires: 2010-10-19
Abstract
Abstract An overload protection drive circuit for a power transistor has a sensing transistor (T2) for providing a drain source bypass for the power transistor (T1). The bypass is formed by a first resistor (R11) in series with the drain and a second resistor (R10) in series with the source. The voltage developed across one of the resistors (R10, R11) is arranged to trigger a switching circuit (15) to inhibit drive upon occurrence of a predetermined voltage to prevent excessive drain source current.
Inventors
- 👤 Franciscus Adrianus Cornelis Maria Schoofs
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 15:50
CPC Classifications
H; H02; H02H; H02H9/00; H02H9/02; H03; H03K; H03K17/00; H03K17/08; H03K17/082; H03K17/0822
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
85 words
An overload protection drive circuit for a power transistor, characterized in a sensing transistor (T2) for providing a drain source bypass for the power transistor (T1), which bypass is formed by a first resistor (R11) in series with the drain and a second resistor (R10) in series with the source and wherein the voltage developed across one of the resistors (R10, R11) is arranged to trigger a switching circuit (19,20,21,25) to inhibit drive upon occurrence of a predetermined voltage to prevent excessive drain source current.
Claim 2
Dependent Claim
85 words
An overload protection drive circuit for a power transistor, characterized in a sensing transistor (T2) for providing a drain source bypass for the power transistor (T1), which bypass is formed by a first resistor (R11) in series with the drain and a second resistor (R10) in series with the source and wherein the voltage developed across one of the resistors (R10, R11) is arranged to trigger a switching circuit (19,20,21,25) to inhibit drive upon occurrence of a predetermined voltage to prevent excessive drain source current.
Claim 3
Dependent Claim
35 words
A drive circuit as claimed in Claim 1, characterised in that the switching circuit comprises a comparator (19) coupled with said one of the resistors for effecting switching when a preset reference voltage is exceeded.
Claim 4
Dependent Claim
41 words
A drive circuit as claimed in Claim 2, characterised in that the switching circuit comprises a latch (20) having an input coupled with the output of the comparator (19) and an output for inhibiting drive upon occurrence of said predetermined voltage.
Claim 5
Dependent Claim
46 words
A drive circuit as claimed in any one of the preceding claims, characterised in that means (30,31) are provided to ensure that the switching circuit is enabled to permit inhibition of drive only when the gate voltage of the power transistor approaches the maximum permitted value.
Claim 6
Dependent Claim
65 words
A drive circuit as claimed in Claim 4, characterised in that said means to ensure that the switching circuits is enabled comprises an AND gate (30) having an input coupled with the gate of the power transistor (T1) via a comparator (31) and a second input coupled with said one of the resistors via a comparator (19) and an output coupled with a latch (20).
Claim 7
Dependent Claim
24 words
A drive circuit as claimed in any one of the preceding Claims, characterised in that it is fabricated on a single integrated circuit chip.
Claim 8
Dependent Claim
43 words
A power supply circuit, characterised in the combination of a power transistor (T1) and an overload protection drive circuit as claimed in any one of the preceding claims forming a drain source bypass for the power transistor to prevent excessive drain source current.
Claim 9
Dependent Claim
49 words
A half bridge power supply circuit, characterised in the combination of two power transistors connected in series and an overload protection drive circuit as claimed in anyone of Claims 1 to 6 forming a drain source bypass for one of the power transistors to prevent excessive drain source current.
Claim 10
Dependent Claim
65 words
A full bridge power supply circuit comprising two branches each including two power transistors connected in series, characterised in the combination of the bridge circuit with two overload protection drive circuits as claimed in any one of Claims 1 to 6 one for each branch each forming a drain source bypass for one of the power transistors in that branch to prevent excessive source current.
Claim 11
Dependent Claim
49 words
A multiphase drive circuit, characterised in that provision for each phase of a power transistor for supplying phase current and an overload protection drive circuit as claimed in anyone of Claims 1 to 6 forming a drain source bypass for the power transistor to prevent excessive drain source current.
References Cited (Backward Citations)
No citation records indexed.
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