Predriver short protection
AssigneeTexas Instruments Incorporated
InventorsShyamsunder BALASUBRAMANIAN, Toshio YAMANAKA, Toru TANAKA, Mayank GARG
Life of this patent
Estimating the term…
Abstract
A gate driver circuit includes a comparator and a gate driver. The comparator is configured to detect a short circuit in a first power field effect transistor (FET). The gate driver is configured to drive a gate of the first power FET by generating a first signal at a first drive current. In response to the comparator detecting a short circuit in the first power FET, the gate driver is further configured to pulse the first signal at a first pulldown current. After the pulse has ended, the gate driver is further configured to drive the gate of the first power FET at a first hold current. The first hold current is less than the first pulldown current.
Claims14
A gate driver circuit, comprising:
- a first power field effect transistor having a gate, a drain and a source;
- a gate driver having a control input and a drive output coupled to the gate of the first power field effect transistor;
- comparator circuitry having an input coupled to the gate of the first power field effect transistor, an input coupled to the source of the first power field effect transistor, and a short circuit output signal coupled to the control input of the gate driver;
- in the absence of a short circuit output signal, the gate driver applying a drive current to the gate of the first power field effect transistor and applying a first pull down current to the gate of the first power field effect transistor in response to a control signal on the control input;
- and
- in response to a short circuit output signal, the gate driver applying the first pull down current to the gate of the first power field effect transistor for a duration of time based on how long the first pulldown current may be applied before components of the gate driver circuit begin to fail, and then applying a hold down current to the gate of the first power field effect transistor at a magnitude much less than the first pull down current.
4-5. (canceled)
A control system, comprising:
- a microcontroller having a short circuit signal input and a driver control signal output;
- an electric motor having power inputs;
- a first power field effect transistor having a gate, a drain and a source and being coupled to a power input of the electric motor;
- a gate driver having a control input coupled to the control output of the microcontroller and a drive output coupled to the gate of the first power field effect transistor;
- comparator circuitry having an input coupled to the gate of the first power field effect transistor, an input coupled to the source of the first power field effect transistor, and a short circuit output signal coupled to the short circuit signal input of the microcontroller;
- in the absence of a short circuit output signal, the gate driver applying a drive current to the gate of the first power field effect transistor and applying a first pull down current to the gate of the first power field effect transistor in response to a control signal on the control input;
- and
- in response to a short circuit output signal, the gate driver applying the first pull down current to the gate of the first power field effect transistor for a duration of time based on how long the first pulldown current may be applied before components of the gate driver circuit begin to fail, and then applying a hold down current to the gate of the first power field effect transistor at a magnitude much less than the first pull down current.
8-13. (canceled)
A method of protecting gate driver circuits from short circuits, comprising:
- comparing voltages at a first power field effect transistor for detecting a short circuit at the first power field effect transistor;
- in the absence of detecting a short circuit, applying a drive current to a gate of the first power field effect transistor and applying a first pull down current to the gate of the first power field effect transistor in response to a control signal;
- and
- in response to detecting a short circuit, applying the first pull down current to the gate of the first power field effect transistor for a duration of time based on how long the first pulldown current may be applied before components of the gate driver circuit begin to fail, and then applying a hold down current to the gate of the first power field effect transistor at a magnitude much less than the first pull down current.
(canceled)
Dependencies are inferred from the claim text.