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US 5,852,538 AGranted
Power element driving circuit
AssigneeSharp Kabushiki Kaisha
InventorYoshitugu Masui
Life of this patent
Estimating the term…
Abstract
A power element driving circuit is provided with an abnormality detecting circuit which detects an occurrence of abnormality in an IGBT (power element) or a short-circuit load based on a collector voltage of the IGBT, and controls a gate voltage control circuit so as to gradually reduce a gate voltage of the IGBT. According to the described arrangement, the IGBT can be protected from breakdown caused by short-circuit current increased by itself due to an inverse current from the load. Moreover, since an occurrence of abnormality in the IGBT is detected after starting up the IGBT, the rise time for the IGBT can be reduced, thereby preventing the thermal breakdown or power loss which may occur when a long rise time is required.
Claims22
A power element driving circuit comprising:
- driving means for driving a power element, said driving means includes a circuit having an n-p-n transistor and a p-n-p transistor which are complementary connected in series, and a control electrode of said power element connected to an emitter of said n-p-n transistor and to an emitter of said p-n-p transistor, the emitter of said n-p-n transistor and the emitter of said p-n-p transistor being connected, said driving means providing a driving voltage to said power element, said driving voltage being the only signal provided to said control electrode of said power element;
- control means for controlling said driving means, said control means being configured to send a control signal to a base of said n-p-n transistor and to a base of said p-n-p transistor, the base of said n-p-n transistor and the base of said p-n-p transistor being connected, said control signal controlling delivery of said driving voltage to said control electrode of said power element;
- abnormality detection means for detecting an occurrence of abnormality in said power element or a load connected to said power element;
- and
- voltage drop control means for controlling said control means so as to gradually lower said driving voltage of said power element when the occurrence of abnormality in said power element or the load connected to said power element is detected by said abnormality detection means.
2 more elements
A power element driving circuit comprising:
- driving means for driving an insulated gate bipolar transistor, said driving means includes a circuit wherein a n-p-n and a p-n-p transistor are complementary connected in series, and a gate of said insulated gate bipolar transistor is connected to an emitter of said n-p-n transistor and to an emitter of said p-n-p transistor, the emitter of said n-p-n transistor and the emitter of said p-n-p transistor being connected, said driving means providing a driving voltage to said insulated gate bipolar transistor, said driving voltage being the only signal provided to said gate of said insulated gate bipolar transistor;
- control means for controlling said driving means, said control means being configured to output a control signal to a base of said n-p-n transistor and to a base of said p-n-p transistor, the base of said n-p-n transistor and said p-n-p transistor being connected, said control signal controlling delivery of said driving voltage to said gate of said insulated gate bipolar transistor;
- abnormality detection means for detecting an occurrence of abnormality in said insulated gate bipolar transistor or in a load connected to said insulated gate bipolar transistor;
- and
- voltage drop control means for controlling said control means to gradually lower said driving voltage of said insulated gate bipolar transistor when the occurrence of abnormality in said insulated gate bipolar transistor or the load is detected by said abnormality detection means.
2 more elements
A optically coupled element being an integrated circuit, comprising:
- a light emitting element;
- a light receiving element for receiving light emitted from said light emitting element;
- driving means for driving a power element, said driving means includes a circuit having an n-p-n transistor and a p-n-p transistor which are complementary connected in series, and a control electrode of said power element connected to an emitter of said n-p-n transistor and to an emitter of said p-n-p transistor, the emitter of said n-p-n transistor and the emitter of said p-n-p transistor being connected, said driving means providing a driving voltage to said power element, said driving voltage being the only signal provided to said control electrode of said power element;
- control means for controlling said driving means based on an output from said light receiving element, said control means being configured to send a control signal to a base of said n-p-n transistor and to a base of said p-n-p transistor, the base of said n-p-n transistor and the base of said p-n-p transistor being connected, said control signal controlling delivery of said driving voltage to said control electrode of said power element;
- abnormality detection means for detecting an occurrence of abnormality in said power element or a load connected to said power element;
- and
- voltage drop control means for controlling said control means so as to gradually lower said driving voltage of said power element when the occurrence of abnormality in said power element or the load is detected by said abnormality detection means,
- wherein said light emitting element, said light receiving element, said driving means, said control means, said abnormality detection means and said voltage drop control means are formed on a single chip.
5 more elements
A optically coupled element being an integrated circuit, comprising:
- a light emitting element;
- a light receiving element for receiving light emitted from said light emitting element;
- driving means for driving an insulated gate bipolar transistor, said driving means includes a circuit wherein a n-p-n and a p-n-p transistor are complementary connected in series, and a gate of said insulated gate bipolar transistor is connected to an emitter of said n-p-n transistor and to an emitter of said p-n-p transistor, the emitter of said n-p-n transistor and the emitter of said p-n-p transistor being connected, said driving means providing a driving voltage to said insulated gate bipolar transistor, said driving voltage being the only signal provided to said gate of said insulated gate bipolar transistor;
- control means for controlling said driving means based on an output from said light receiving element, said control means being configured to output a control signal to a base of said n-p-n transistor and to a base of said p-n-p transistor, the base of said n-p-n transistor and said p-n-p transistor being connected, said control signal controlling delivery of said driving voltage to said gate of said insulated gate bipolar transistor;
- abnormality detection means for detecting an occurrence of abnormality in said insulated gate bipolar transistor or a load connected to said insulated gate bipolar transistor;
- and
- voltage drop control means for controlling said control means so as to gradually lower said driving voltage of said insulated gate bipolar transistor when the occurrence of abnormality in said insulated gate bipolar transistor or the load is detected by said abnormality detection means,
- wherein said light emitting element, said light receiving element, said driving means, said control means, said abnormality detection means and said voltage drop control means are formed on a single chip.
5 more elements
A power element driving circuit comprising:
- driving means for driving a power element, said driving means includes a circuit having an n-p-n transistor and a p-n-p transistor which are complementary connected in series, and a control electrode of said power element connected to an emitter of said n-p-n transistor and to an emitter of said p-n-p transistor, the emitter of said n-p-n transistor and the emitter of said p-n-p transistor being connected, said driving means providing a driving voltage to said power element, said driving voltage being the only signal provided to said control electrode of said power element;
- control means for controlling said driving means, said control means being configured to send a control signal to a base of said n-p-n transistor and to a base of said p-n-p transistor, the base of said n-p-n transistor and the base of said p-n-p transistor being connected, said control signal controlling delivery of said driving voltage to said control electrode of said power element;
- abnormality detection means for detecting an occurrence of abnormality in said power element or a load connected to said power element;
- and
- voltage drop control means including,
- a constant current circuit for pulling in a current from said control electrode of said power element;
- and
- a switching circuit for stopping an operation by said control means and activating said constant current circuit based on an abnormality detecting signal from said abnormality detection means, whereby said voltage drop control means controls said control means so as to gradually lower said driving voltage of said power element when the occurrence of abnormality in said power element or the load connected to said power element is detected by said abnormality detection means.
5 more elements
A power element driving circuit comprising:
- driving means for driving an insulated gate bipolar transistor, said driving means includes a circuit wherein a n-p-n and a p-n-p transistor are complementary connected in series, and a gate of said insulated gate bipolar transistor is connected to an emitter of said n-p-n transistor and to an emitter of said p-n-p transistor, the emitter of said n-p-n transistor and the emitter of said p-n-p transistor being connected, said driving means providing a driving voltage to said insulated gate bipolar transistor, said driving voltage being the only signal provided to said gate of said insulated gate bipolar transistor;
- control means for controlling said driving means, said control means being configured to output a control signal to a base of said n-p-n transistor and to a base of said p-n-p transistor, the base of said n-p-n transistor and said p-n-p transistor being connected, said control signal controlling delivery of said driving voltage to said gate of said insulated gate bipolar transistor;
- abnormality detection means for detecting an occurrence of abnormality in said insulated gate bipolar transistor or in a load connected to said insulated gate bipolar transistor;
- and
- voltage drop control means including
- a constant current circuit for pulling in a current from a said gate of said insulated gate bipolar transistor, and
- a switching circuit for stopping an operation by said control means and activating said constant current circuit based on an abnormality detecting signal from said abnormality detection means,
- whereby said voltage drop control means controls said control means to gradually lower said driving voltage of said insulated gate bipolar transistor when the occurrence of abnormality in said insulated gate bipolar transistor or the load is detected by said abnormality detection means.
5 more elements
A optically coupled element being an integrated circuit, comprising:
- a light emitting element;
- a light receiving element for receiving light emitted from said light emitting element;
- driving means for driving a power element, said driving means includes a circuit having an n-p-n transistor and a p-n-p transistor which are complementary connected in series, and a control electrode of said power element is connected to an emitter of said n-p-n transistor and to an emitter of said p-n-p transistor, the emitter of said n-p-n transistor and the emitter of said p-n-p transistor being connected, said driving means providing a driving voltage to said power element, said driving voltage being the only signal provided to said control electrode of said power element;
- control means for controlling said driving means based on an output from said light receiving element, said control means being configured to send a control signal to a base of said n-p-n transistor and to a base of said p-n-p transistor, the base of said n-p-n transistor and said p-n-p transistor being connected, said control signal controlling delivery of said driving voltage to said control electrode of said power element;
- abnormality detection means for detecting an occurrence of abnormality in said power element or a load connected to said power element;
- and
- voltage drop control means for controlling said control means so as to gradually lower said driving voltage of said power element when the occurrence of abnormality in said power element or the load is detected by said abnormality detection means, said voltage drop control means including a constant current circuit for pulling in a current from said control electrode of said insulated power element, and
- a switching circuit for stopping an operation by said control means and activating said constant current circuit based on an abnormality detecting signal from said abnormality detection means,
- wherein said light emitting element, said light receiving element, said driving means, said control means, said abnormality detection means and said voltage drop control means are formed on a single chip.
6 more elements
An optically coupled element being an integrated circuit, comprising:
- a light emitting element;
- a light receiving element for receiving light emitted from said light emitting element;
- driving means for driving an insulated gate bipolar transistor, said driving means includes a circuit wherein a n-p-n and a p-n-p transistor are complementary connected in series, and a gate of said insulated gate bipolar transistor is connected to an emitter of said n-p-n transistor and to an emitter of said p-n-p transistor, the emitter of said n-p-n transistor and the emitter of said p-n-p transistor being connected, said driving means providing a driving voltage to said insulated gate bipolar transistor, said driving voltage being the only signal provided to said gate of said insulated gate bipolar transistor;
- first control means for driving said insulated gate bipolar transistor, said first control means being configured to output a control signal to a base of said n-p-n transistor and to a base of said p-n-p transistor, the base of said n-p-n transistor and said p-n-p transistor being connected, said control signal controlling delivery of said driving voltage to said gate of said insulated gate bipolar transistor;
- second control means for controlling said driving means based on an output from said light receiving element;
- abnormality detection means for detecting an occurrence of abnormality in said insulated gate bipolar transistor or a load connected to said insulated gate bipolar transistor;
- and
- voltage drop control means for controlling said first control means so as to gradually lower said driving voltage of said insulated gate bipolar transistor when the occurrence of abnormality in said insulated gate bipolar transistor or the load is detected by said abnormality detection means, said voltage drop control means including a constant current circuit for pulling in a current from said gate of said insulated gate bipolar transistor, and
- a switching circuit for stopping an operation by said first control means and activating said constant current circuit based on an abnormality detecting signal from said abnormality detection means,
- wherein said light emitting element, said light receiving element, said driving means, said first and second control means, said abnormality detection means and said voltage drop control means are formed on a single chip.
7 more elements
Dependencies are inferred from the claim text.