EP0190925A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A protection circuit for an insulated gate bipolar transistor
Assignee: Toshiba Corp
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Filing: 1986-02-05
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Granted: —
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Expires: 2006-02-05
Abstract
Abstract A driving circuit for an insulated gate bipolar transistor (IGBT) (1) which has a power source (4, 5), a gate voltage input circuit (6, 7) which supplies the voltage to a gate terminal of IGBT, a detecting circuit (16, 17, 41, 42) for detecting a collector to emitter voltage of the IGBT and an adjusting circuit (13, 14, 10, 18, 21, 44) for lowering the control signal.When an abnormality is detected by the detecting circuit the adjusting circuit performs a dropping operation of the gate voltage of the IGBT immediately after the detection or after the passage of a predetermined time following the application of the On signal to the gate.
Inventors
- 👤 Chihiro Okado
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 22:04
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/08; H03K17/082; H03K17/0828
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
100 words
A driving circuit for an insulated gate bipolar transistor (1) comprising a power source (4) for supplying a constant voltage and a gate voltage input circuit (6, 7) for applying said constant voltage to a gate terminal of an insulated gate bipolar transistor (1) according to a control signal, characterized in that: said driving circuit further comprises a detecting circuit (41, 42) which detects a collector to emitter voltage of said insulated gate bipolar transistor (1), and an adjusting circuit for lowering the control signal voltage according to the output of the detecting circuit, whereby said gate voltage is reduced.
Claim 2
Dependent Claim
100 words
A driving circuit for an insulated gate bipolar transistor (1) comprising a power source (4) for supplying a constant voltage and a gate voltage input circuit (6, 7) for applying said constant voltage to a gate terminal of an insulated gate bipolar transistor (1) according to a control signal, characterized in that: said driving circuit further comprises a detecting circuit (41, 42) which detects a collector to emitter voltage of said insulated gate bipolar transistor (1), and an adjusting circuit for lowering the control signal voltage according to the output of the detecting circuit, whereby said gate voltage is reduced.
Claim 3
Dependent Claim
28 words
A driving circuit according to claim 1, wherein said adjusting circuit comprises an emitter follower (44) for passing a collector current according to its emitter to base voltage.
Claim 4
Dependent Claim
34 words
A driving circuit according to claim 2, wherein said emitter to base voltage is obtained by a bleeder (41, 42) which divides the collector to emitter voltage of said insulated gate bipolar transistor (1).
Claim 5
Dependent Claim
42 words
A driving circuit according to claim 1, which further comprises gate voltage drop detecting means (51, 52a, 52b, 54 and 55), whereby said insulated-gate bipolar transistor (1) is turned off when the gate voltage drop operation continues longer than a predetermined period.
Claim 6
Dependent Claim
30 words
A driving circuit according to claim 4, wherein said gate voltage drop detecting means comprises a current detector (56) which detects the collector current of insulated gate bipolar transistor (1).
Claim 7
Dependent Claim
115 words
A driving circuit for an insulated gate bipolar transistor (1) comprising a power source (4, 5) for supplying a constant voltage and a gate voltage input circuit (6, 7) for applying said constant voltage to a gate terminal of an insulated gate bipolar transistor according to a control siganl, characterized in that: said driving circuit further comprises a detecting circuit (16. 17) for detecting a collector to emitter voltage of said insulated gate bipolar transistor, and an adjusting circuit (13, 14, 10, 18, 2 1) for lowering the gate voltage under the condition that the detecting circuit outputs an enable signal and a predetermined time passes after turn on signal is applied to the gate.
Claim 8
Dependent Claim
115 words
A driving circuit for an insulated gate bipolar transistor (1) comprising a power source (4, 5) for supplying a constant voltage and a gate voltage input circuit (6, 7) for applying said constant voltage to a gate terminal of an insulated gate bipolar transistor according to a control siganl, characterized in that: said driving circuit further comprises a detecting circuit (16. 17) for detecting a collector to emitter voltage of said insulated gate bipolar transistor, and an adjusting circuit (13, 14, 10, 18, 2 1) for lowering the gate voltage under the condition that the detecting circuit outputs an enable signal and a predetermined time passes after turn on signal is applied to the gate.
Claim 9
Dependent Claim
29 words
7 . A driving circuit according to claim 6, wherein said adjusting circuit comprises an emitter follower (14) which sends a current according to its emitter to base voltage.
Claim 10
Dependent Claim
36 words
8 . A driving circuit according to claim 8, wherein said emitter to base voltage is obtained by a bleeder (16, 17) which divides the collector to emitter voltage of said insulated gate bipolar transistor (1).
Claim 11
Dependent Claim
44 words
9 . A driving circuit according to claim 6, wherein said adjusting circuit comprises a differential circuit composed of a capacitor (18) and a resistor (20), whereby said gate voltage is not lowered during the period when said differential circuit differentiates said ON signal.
Claim 12
Dependent Claim
40 words
A driving circuit according to claim 11, which further comprises gate voltage drop detecting means (13a, 13b, 23, 22), whereby said insulated gate bipolar transistor (1) is turned-off when the gate voltage drop operation continues longer than the predetermined period.
References Cited (Backward Citations)
No citation records indexed.
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