Integrated circuit-based drive circuit for driving voltage-controlled switching device and method of manufacturing the drive circuit

• US 8,704,556 B2
• Filed: 12/13/2011
• Issued: 04/22/2014
• Est. Priority Date: 12/14/2010
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Hamanaka, Yoshiyuki, Maebara, Tsuneo, Nagata, Junichi, Muraho, Tomoyuki, Itou, Akito
• Primary Examiner(s): Donovan, Lincoln
• Assistant Examiner(s): Almo, Khareem E
• Application Number:
  US13/324,153
• Publication Number:
  US 20120146613A1
• Time in Patent Office: 861 Days
• Field of Search: None
• US Class Current: 327/109
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• CPC Class Codes: H03K 17/567 Circuits characterised by the use of more than one type of semiconductor device, e.g. BIMOS, composite devices such as IGBT
• CPC Class Codes: H03K 17/602 in integrated circuits
• CPC Class Codes: H03K 17/6877 the control circuit comprising active elements different from those used in the output circuit
• CPC Class Codes: H03K 2017/0806 against excessive temperature

Abstract

A drive circuit supplies a charging current via a charging path to drive the control terminal of a voltage-controlled switching device, with a resistor and a switching device being connected in series in the charging path. A control circuit in an integrated circuit of the drive circuit operates an internal switching device such as to selectively enable/interrupt the charging current and to regulate the voltage drop across the resistor to a fixed value. The switching device connected in the charging path can be readily changed from the internal switching device to an external switching device, in accordance with the operating requirements of the driven switching device.

Claims

1. A drive circuit for driving a voltage-controlled type of driven switching device, the drive circuit comprising an integrated circuit and including a charging path for supplying a charging current to a control terminal of said driven switching device, wherein said drive circuit comprises a resistor and an external switching device, said resistor connected in series with an input terminal and an output terminal of said external switching device in said charging path, and wherein said integrated circuit comprises:

an internal switching device connected in a Darlington configuration to said external switching device, and

a control circuit configured for applying a control signal to a control terminal of said internal switching device, for regulating a voltage drop across said resistor to a predetermined value.

2. A drive circuit according to claim 1, wherein said control circuit is responsive to an externally supplied drive operation signal for controlling said internal switching device to selectively enable and interrupt passage of current through said charging path.

3. A drive circuit according to claim 1, wherein:

said charging path serves for supplying a positive charge to said control terminal of said driven switching device, and

an output terminal of said internal switching device is connected to an output terminal of said driven switching device.

4. A drive circuit according to claim 1, wherein:

said charging path serves for supplying a positive charge to said control terminal of said driven switching device, and

an output terminal of said internal switching device is connected to said output terminal of said external switching device.

5. A drive circuit according to claim 1, wherein:

said charging path serves for supplying a negative charge to said control terminal of said driven switching device, and

an output terminal of said internal switching device is connected to a control terminal of said external switching device.

6. A drive circuit according to claim 1, wherein at least a part of said resistor is disposed external to said integrated circuit.

7. A drive circuit for driving a voltage-controlled type of driven switching device, the drive circuit comprising an integrated circuit and including a charging path for supplying a charging current to a control terminal of said driven switching device, said integrated circuit including an internal switching device controllable for regulating a value of a current, and

a control circuit configured to produce a control signal from an output terminal, for selectively enabling and interrupting a flow of said charging current;

wherein said integrated circuit comprises a changeover circuit responsive to a changeover signal applied to an external input terminal of said integrated circuit for selectively establishing a first connection condition in which said output terminal of said control circuit is connected to an internal element of said integrated circuit for thereby connecting said internal switching device of said integrated circuit into said charging path, and a second connection condition in which said output terminal of the control circuit is connected to an external output terminal of said integrated circuit.

8. A drive circuit according to claim 7, comprising a resistor connected in said charging path, wherein:

a control terminal of said internal switching device becomes connected to an output terminal of said changeover circuit while said first connection condition is established, and

said control circuit is configured to regulate a voltage drop across said resistor to a predetermined value.

9. A drive circuit according to claim 8, wherein said external input terminal is dedicated to said changeover operation signal.

10. A drive circuit according to claim 8, wherein:

said drive circuit is operable for driving a single driven switching device or a plurality of driven switching devices connected in parallel,

said integrated circuit comprises a plurality of external status detection input terminals dedicated to status detection signals expressing detected status values of respective ones of said plurality of driven switching devices, and

said integrated circuit comprises a changeover operation circuit configured to judge an input signal condition of a specific one of said external status detection input terminals, and to operate said changeover circuit for connecting said output terminal of said control circuit to said external output terminal of said integrated circuit when it is judged that a status detection signal is being applied to said specific external status detection input terminal.

11. A drive circuit according to claim 8, wherein a value of a power supply voltage applied to a power supply input terminal of said integrated circuit is set to respectively different values in accordance with whether or not said control circuit is required to be connected to said external output terminal, and wherein said integrated circuit comprises a changeover operation circuit configured to operate said changeover circuit based on judging said value of voltage applied to said power supply input terminal.

12. A drive circuit according to claim 8, wherein said external input terminal serves in common for inputting a drive operation signal for commanding said control circuit to effect said enabling and interruption of said drive current and for inputting said changeover operation signal, and wherein integrated circuit comprises a changeover operation circuit configured to operate said changeover circuit in accordance with said changeover operation signal, based on a difference between said drive operation signal and said changeover operation signal.

13. A drive circuit according to claim 12, wherein said changeover operation circuit is configured to operate said changeover circuit in accordance with said changeover operation signal only during an interval of predetermined duration, said interval occurring prior to a commencement of applying said drive operation signal to said external input terminal.

14. A drive circuit according to claim 8, wherein at least a part of said resistor is disposed external to said integrated circuit.

15. A method of manufacturing a drive circuit incorporating an integrated circuit, the drive circuit configured for driving a voltage-controlled type of driven switching device by supplying a charging current through a charging path to charge a control terminal of said driven switching device, the method comprising:

a formation step of forming an internal switching device and a control circuit in said integrated circuit, said control circuit being operable for controlling said internal switching device to selectively enable and interrupt a flow of said charging current;

a judgement step of judging whether or not said charging current is to pass via said internal switching device, said judgement being based upon utilization requirements of said driven switching device;

an external connection step, executed when a negative decision is reached in said judgement step, of

providing an external switching device outside said integrated circuit, and

connecting said external switching device to said control terminal of the driven switching device and to said integrated circuit such as to establish said charging path as a path via said external switching device; and

an internal connection step, executed when an affirmative decision is reached in said judgement step, of connecting said internal switching device to said control terminal of said driven switching device such as to establish said charging path as a path via said internal switching device.

16. A method according to claim 15, further comprising a resistor connected in a flow path of said charging current, wherein:

said control circuit is configured to produce control signal for controlling a voltage drop across said resistor to a predetermined value.

17. A method according to claim 15, wherein:

said internal switching device and said external switching device comprise respective transistor devices, and

when said charging path is to be established via said external switching device, said internal switching device is connected to said external switching device in a Darlington configuration.

18. A method according to claim 15, further comprising a resistor connected in series in said charging path, wherein said formation step applied to said integrated circuit comprises steps of:

forming said control circuit such as to regulate a voltage drop across said resistor to a predetermined value,

forming a changeover circuit, controllable for effecting changeover between connecting an output terminal of said control circuit to a control terminal of said internal switching device and to a control terminal of said external switching device, and

forming a changeover operation circuit configured to operate said changeover circuit in accordance with a signal applied to an external input terminal of said integrated circuit.