Gate driver circuit, motor driver circuit, and hard disk apparatus
AssigneeRohm Co., Ltd.
InventorHisashi Sugie
Life of this patent
Estimating the term…
Abstract
A gate driver circuit drives a switching transistor. A variable current source generates a reference current configured to switch between a first current amount and a second current amount smaller than the first current amount. A current distribution circuit is configured to switch between a source enabled state in which a source current proportional to the reference current is sourced to a gate node of the switching transistor and a disabled state in which the source current is made equal to zero. A first transistor fixes the gate node of the switching transistor to a high voltage in an on-state of the first transistor. A second transistor fixes the gate node of the switching transistor to a low voltage in an on-state of the second transistor.
Claims16
A gate driver circuit that drives a switching transistor, the gate driver circuit comprising:
- a variable current source configured to:
- generate a reference current;
- and
- control switching between a first current amount of the reference current and a second current amount of the reference current smaller than the first current amount, wherein
- the switching is based on a transition of a voltage level of a gate voltage at a gate node of the switching transistor from a first voltage level to a second voltage level higher than the first voltage level,
- the reference current is switched to the first current amount during the transition of the voltage level of the gate voltage at the gate node of the switching transistor from the first voltage level to the second voltage level, and
- the reference current is switched to the second current amount after the transition of the voltage level of the gate voltage at the gate node of the switching transistor from the first voltage level to the second voltage level;
- a current distribution circuit configured to switch between a source enabled state and a disabled state, wherein
- a source current proportional to the reference current having the first current amount or the second current amount is sourced to the gate node of the switching transistor in the source enabled state, and
- the source current is made equal to zero in the disabled state;
- a first transistor configured to fix the gate node of the switching transistor to the second voltage level in an on-state of the first transistor;
- and
- a second transistor configured to fix the gate node of the switching transistor to the first voltage level in an on-state of the second transistor.
A gate driver circuit that drives a switching transistor, the gate driver circuit comprising:
- a variable current source configured to:
- generate a reference current;
- and
- control switching between a first current amount of the reference current and a second current amount of the reference current smaller than the first current amount, wherein
- the switching is based on a transition of a voltage level of a gate voltage at a gate node of the switching transistor from a first voltage level to a second voltage level higher than the first voltage level,
- the reference current is switched to the first current amount during the transition of the voltage level of the gate voltage at the gate node of the switching transistor from the first voltage level to the second voltage level, and
- the reference current is switched to the second current amount after the transition of the voltage level of the gate voltage at the gate node of the switching transistor from the first voltage level to the second voltage level;
- a current distribution circuit configured to switch between a sink enabled state and a disabled state, wherein
- a sink current proportional to the reference current having the first current amount or the second current amount is sunk from the gate node of the switching transistor in the sink enabled state, and
- the sink current is made equal to zero in the disabled state;
- a first transistor configured to fix the gate node of the switching transistor to the second voltage level in an on-state of the first transistor;
- and
- a second transistor configured to fix the gate node of the switching transistor to the first voltage level in an on-state of the second transistor.
Dependencies are inferred from the claim text.