Switch matrix drive circuit for a power element
AssigneeMitsubishi Electric Corporation
InventorYuji Miyazaki
Life of this patent
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Abstract
A drive circuit for an IGBT includes an H-bridge circuit using first to fourth switch elements. When a control unit receives a command for changing the IGBT from an on state to an off state, it switches states of the first to fourth switch elements from a first state in which the first and fourth switch elements are in an on state and the second and third switch elements are in an off state to a second state in which the first and fourth switch elements are in the off state and the second and third switch elements are in the on state. This structure of the drive circuit can apply a reverse bias to the IGBT from a single power supply.
Claims16
A drive circuit for a power element, said power element controlling a main current flowing between first and second main electrodes according to a signal provided to a control electrode, comprising:
- a power supply connected between first and second nodes;
- a switch matrix circuit configured to connect said control electrode selectively to one of said first and second nodes, and to connect said second main electrode selectively to one of said first and second nodes;
- and
- a control unit for controlling said switch matrix circuit according to an input signal provided for switching said power element between on and off states, wherein,
- when said input signal changes to switch said power element from the on state to the off state, said control unit switches the state of said switch matrix circuit from a first state for connecting said control electrode to said first node and connecting said second main electrode to said second node to a second state for connecting said control electrode to said second node and connecting said second main electrode to said first node,
- when said input signal changes to switch said power element from the off state to the on state, said control unit switches the state of said switch matrix circuit from said second state to said first state,
- said control unit switches the state of said switch matrix circuit to a third or fourth state at least one of during switching the state of said switch matrix circuit from said first state to said second state and during switching the state of said switch matrix circuit from said second state to said first state,
- in said third state, a conductive state is established between said first node and said control electrode and between said first node and said second main electrode, and a non-conductive state is established between said second node and said control electrode and between said second node and said second main electrode, and
- in said fourth state, a conductive state is established between said second node and said control electrode and between said second node and said second main electrode, and a non-conductive state is established between said first node and said control electrode and between said first node and said second main electrode.
A drive circuit for a power element, said power element controlling a main current flowing between first and second main electrodes according to a signal provided to a control electrode comprising:
- a power supply connected between first and second nodes;
- a switch matrix circuit configured to connect said control electrode selectively to one of said first and second nodes, and to connect said second main electrode selectively to one of said first and second nodes;
- and
- a control unit for controlling said switch matrix circuit according to an input signal provided for switching said power element between on and off states, wherein,
- when said input signal changes to switch said power element from the on state to the off state, said control unit switches the state of said switch matrix circuit from a first state for connecting said control electrode to said first node and connecting said second main electrode to said second node to a second state for connecting said control electrode to said second node and connecting said second main electrode to said first node,
- said switch matrix circuit includes:
- a first switch element connected between said control electrode and said first node;
- a second switch element connected between said control electrode and said second node;
- a third switch element connected between said second main electrode and said first node;
- and
- a fourth switch element connected between said second main electrode and said second node,
- said control unit in said first state turns on said first and fourth switch elements, and turns off said second and third switch elements, and said control unit in said second state turns off said first and fourth switch elements, and turns on said second and third switch elements, and
- said drive circuit for the power element further comprises a constant voltage unit arranged on at least one of a path extending from said first node through said third switch element to said second main electrode and a path extending from said control electrode through said second switch element to said second node for sharing a voltage between said first and second nodes.
Dependencies are inferred from the claim text.