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US 7,459,945 B2Granted
Gate driving circuit and gate driving method of power MOSFET
AssigneeKabushiki Kaisha Toshiba
InventorIchiro Omura
Life of this patent
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Abstract
A gate driving circuit and method which increases the switching frequency by use of a switching control circuit which controls operations of a first, second, third, and fourth switches. The switching control circuit performs switching control of a power MOSFET when the MOSFET is to be turned on, so that a period exists when the first and fourth switches are simultaneously ON. The switching circuit also performs switching control when a MOSFET is to be turned off, so that a period exists when the second and third switches are simultaneously ON.
Claims26
A gate driving circuit of a power MOSFET, comprising:
- a first capacitance element connected in series between a first higher voltage terminal and a first lower voltage terminal;
- a first switch connected in series between said first higher voltage terminal and a first node;
- a second switch connected in series between said first node and first lower voltage terminal;
- a first diode connected in parallel with said first switch, and having a cathode connected to said first higher voltage terminal and an anode connected to said first node;
- a second diode connected in parallel with said second switch, and having a cathode connected to said first node and an anode connected to said first lower voltage terminal;
- an inductance element connected in series between said first node and a second node;
- a third switch connected in series between said first higher voltage terminal and second node;
- a fourth switch connected in series between said second node and first lower voltage terminal;
- a third diode connected in parallel with said third switch, and having a cathode connected to said first higher voltage terminal and an anode connected to said second node;
- a fourth diode connected in parallel with said fourth switch, and having a cathode connected to said second node and an anode connected to said first lower voltage terminal;
- and
- a switching control circuit which controls ON/OFF operations of each of said first, second, third, and fourth switches,
- wherein in order to drive a power MOSFET having a drain and source connected between a second higher voltage terminal and a second lower voltage terminal, and a gate connected to said second node,
- said switching control circuit performs switching control such that a period during which said first and fourth switches are simultaneously ON and said fourth switch is turned OFF while said first switch remains ON exists prior to turning on said power MOSFET, and
- performs switching control such that another period during which said second and third switches are simultaneously ON exists prior to turning OFF said power MOSFET.
12 more elements
A gate driving method of a power MOSFET, which drives a power MOSFET by using a gate driving circuit, comprising:
- a first capacitance element connected in series between a first higher voltage terminal and a first lower voltage terminal;
- a first switch connected in series between the first higher voltage terminal and a first node;
- a second switch connected in series between the first node and first lower voltage terminal;
- a first diode connected in parallel with the first switch, and having a cathode connected to the first higher voltage terminal and an anode connected to the first node;
- a second diode connected in parallel with the second switch, and having a cathode connected to the first node and an anode connected to the first lower voltage terminal;
- an inductance element connected in series between the first node and a second node;
- a third switch connected in series between the first higher voltage terminal and second node;
- a fourth switch connected in series between the second node and first lower voltage terminal;
- a third diode connected in parallel with the third switch, and having a cathode connected to the first higher voltage terminal and an anode connected to the second node;
- a fourth diode connected in parallel with the fourth switch, and having a cathode connected to the second node and an anode connected to the first lower voltage terminal;
- and
- a switching control circuit which controls ON/OFF operations of each of the first, second, third, and fourth switches,
- the power MOSFET having a drain and source connected between a second higher voltage terminal and a second lower voltage terminal, and a gate connected to the second node,
- wherein the switching control circuit performs switching control such that a period during which the first and fourth switches are simultaneously ON and the fourth switch is turned OFF while the first switch remains ON exists prior to turning ON said power MOSFET, and
- performs switching control such that another period during which the second and third switches are simultaneously ON exists prior to turning OFF said power MOSFET.
12 more elements
A gate driving circuit of a power MOSFET, comprising:
- a first capacitance element connected in series between a first higher voltage terminal and a first lower voltage terminal;
- a first switch connected in series between said first higher voltage terminal and a first node;
- a second switch connected in series between said first node and first lower voltage terminal;
- a first diode connected in parallel with said first switch, and having a cathode connected to said first higher voltage terminal and an anode connected to said first node;
- a second diode connected in parallel with said second switch, and having a cathode connected to said first node and an anode connected to said first lower voltage terminal;
- an inductance element connected in series between said first node and a second node;
- a third switch connected in series between said first higher voltage terminal and second node;
- a fourth switch connected in series between said second node and first lower voltage terminal;
- a third diode connected in parallel with said third switch, and having a cathode connected to said first higher voltage terminal and an anode connected to said second node;
- a fourth diode connected in parallel with said fourth switch, and having a cathode connected to said second node and an anode connected to said first lower voltage terminal;
- a transformer having a primary winding having a first terminal connected to said second node and a second terminal connected to said first lower voltage terminal;
- and
- a switching control circuit which controls ON/OFF operations of each of said first, second, third, and fourth switches,
- wherein in order to drive a power MOSFET having a drain connected to a second higher voltage terminal, a gate connected to a third terminal of a secondary winding of said transformer, and a source connected to a fourth terminal of the secondary winding of said transformer and to a second lower voltage terminal,
- said switching control circuit performs switching control such that a period during which said first and fourth switches are simultaneously ON and said fourth switch is turned OFF while said first switch remains ON exists prior to turning on said power MOSFET, and
- performs switching control such that another period during which said second and third switches are simultaneously ON exists prior to turning OFF said power MOSFET.
13 more elements
Dependencies are inferred from the claim text.