Inverter apparatus with improved gate drive for power MOSFET

• US 20060192589A1
• Filed: 01/24/2006
• Published: 08/31/2006
• Est. Priority Date: 02/25/2005
• Status: Active Grant

• Current Assignee: Mitsubishi Nichiyu Forklift Co., Ltd. (Mitsubishi Heavy Industries, Ltd.)
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Yamazaki, Hiroyuki, Mori, Kiyoshi, Okazaki, Yoshimi
• Granted Patent: US 7,551,004 B2
• Time in Patent Office: Days
• US Class Current: 326/112
• CPC Class Codes: H03K 17/08122 in field-effect transistor switches
• CPC Class Codes: H03K 17/163 Soft switching

Abstract

An inverter apparatus is composed of a power MOSFET having a source/drain connected to an output terminal, and a gate drive circuit driving a gate of the power MOSFET. The gate drive circuit includes a discharging path connected with the gate of the power MOSFET. The discharging path includes a set of serially-connected diodes which are forward-connected in a direction of a discharge current from the gate of the power MOSFET.

Claims

1. An inverter apparatus comprising:

a power MOSFET having a source/drain connected to an output terminal; and

a gate drive circuit driving a gate of said power MOSFET,

wherein said gate drive circuit includes a discharging path connected with said gate of said power MOSFET, said discharging path comprising a set of serially-connected diodes which are forward-connected in a direction of a discharge current from said gate of said power MOSFET.

2. The inverter apparatus according to claim 1, wherein said serially-connected diodes are silicon diodes.

3. An inverter apparatus comprising:

a first power MOSFET having a source/drain connected to an output terminal;

a second power MOSFET having a source/drain connected to said output terminal;

a first gate drive circuit driving a gate of said first power MOSFET; and

a second gate drive circuit driving a gate of said second power MOSFET;

wherein, during pull-down of said gate of said first power MOSFET followed by pull-up of said gate of said second power MOSFET, said first gate drive circuit drives said gate of said first power MOSFET so that a gate-source voltage of said first power MOSFET ranges from 30% to 70% of a threshold voltage of said first power MOSFET at a timing when said second gate drive circuit drives a gate-source voltage of said second power MOSFET to a threshold voltage of said second power MOSFET.

4. The inverter apparatus according to claim 3, wherein said gate-source voltage of said first power MOSFET ranges from 40% to 60% of said threshold voltage of said first power MOSFET at said timing when said second gate drive circuit drives said gate-source voltage of said second power MOSFET to said threshold voltage of said second power MOSFET.

5. An operating method of an inverter apparatus including:

a first power MOSFET having a first source/drain connected with a first power terminal, and a second source/drain connected with an output terminal; and

a second power MOSFET having a first source/drain connected with a second power terminal, and a second source/drain connected with said output terminal, said method comprising;

pulling down a gate of said first power MOSFET to turn off said first power MOSFET; and

pulling up a gate of said second power MOSFET to turn on said second power MOSFET,

wherein a gate-source voltage of said first power MOSFET ranges from 30% to 70% of a threshold voltage of said first power MOSFET at a timing when a gate-source voltage of said second power MOSFET is driven to a threshold voltage of said second power MOSFET during said pulling up of said gate of said second power MOSFET.