Gate drive circuit, which makes the gate-charge flow back to the load and the main power source

• US 6,967,520 B2
• Filed: 10/14/2003
• Issued: 11/22/2005
• Est. Priority Date: 10/21/2002
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Takehara, Nobuyoshi
• Primary Examiner(s): NGUYEN, MINH T
• Application Number:
  US10/683,588
• Publication Number:
  US 20040075486A1
• Time in Patent Office: 770 Days
• Field of Search: 327108-110, 327374-377, 327387-391, 327/419, 327/427, 327/440, 363/13, 363/21.03, 363/20, 363/97, 323/265, 323/282
• US Class Current: 327/427
• CPC Class Codes: H02M 3/1588 comprising at least one synchronous rectifier element H02M3/1582, H02M3/1584 take precedence
• CPC Class Codes: H03K 17/0406 in composite switches
• CPC Class Codes: H03K 17/04123 in field-effect transistor switches
• 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 17/687 the devices being field-effect transistors
• CPC Class Codes: H03K 2217/0036 Means reducing energy consumption
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A gate driving circuit having: a direct current power source; a driving signal source for outputting signal; a main switch device, having a gate terminal in which the signal outputted from the driving signal source is inputted, for controlling a conduction state between a source terminal and a drain terminal; a load energized when the conduction state between the source and drain terminals becomes a conductive state; a reverse current blocking unit, connected between the driving signal source and the gate terminal; and a regenerative unit, connected between the gate terminal and a high potential side of the power source, which becomes a conductive state when the conduction state between the source and drain terminals is a non-conductive state. A gate-source threshold voltage to obtain the conductive state between the source and drain terminals is set higher than an output voltage of the power source.

Claims

1. A gate driving circuit comprising:

a direct current power source;

a driving signal source for outputting a high-level or low-level signal;

a main switch device, having a gate terminal in which the signal outputted from the driving signal source is inputted, for controlling a conduction state between a source terminal and a drain terminal in correspondence with a level of the signal;

a load energized when the conduction state between the source terminal and the drain terminal becomes conductive;

reverse current blocking means, connected between the driving signal source and the gate terminal, for outputting a signal only in a direction from the driving signal source to the gate terminal; and

regenerative means for regenerating a part of power outputted by the driving signal source in the direct current power source, the regenerative means being connected between the gate terminal and a high potential side of the direct current power source, and the regenerative means becoming conductive when the conduction state between the source terminal and the drain terminal is non-conductive,

wherein a gate-source threshold voltage to make the conduction state between the source terminal and the drain terminal conductive is higher than an output voltage of the direct current power source, and

wherein the regenerative means includes a MOSFET.

2. The gate driving circuit according to claim 1, wherein the main switch device includes an N-channel MOSFET or an N-channel IGBT.

3. The gate driving circuit according to claim 1, wherein the reverse current blocking means includes a diode.

4. A power source circuit comprising:

a gate driving circuit having;

a direct current power source;

a driving signal source for outputting a high-level or low-level signal;

a main switch device, having a gate terminal in which the signal outputted from the driving signal source is inputted, for controlling a conduction state between a source terminal and a drain terminal in correspondence with a level of the signal;

a load energized when the conduction state between the source terminal and the drain terminal becomes conductive;

reverse current blocking means, connected between the driving signal source and the gate terminal, for outputting a signal only in a direction from the driving signal source to the gate terminal; and

regenerative means for regenerating a part of power outputted by the driving signal source in the direct current power source, the regenerative means being connected between the gate terminal and a high potential side of the direct current power source, and the regenerative means becoming conductive when the conduction state between the source terminal and the drain terminal is non-conductive,

wherein in the gate driving circuit, a gate-source threshold voltage to make the conduction state between the source terminal and the drain terminal conductive is higher than an output voltage of the direct current power source,

and wherein when the conduction state between the source terminal and the drain terminal becomes conductive, the output voltage from the direct current power source is supplied to the load, and

wherein the regenerative means includes a MOSFET.

5. The power source circuit according to claim 4, wherein the load includes a primary-side coil of a transformer.

6. The power source circuit according to claim 4, wherein the power source circuit performs DC/AC conversion.

7. The power source circuit according to claim 4, wherein the direct current power source includes plural solar cells which are not serially connected.