Drive circuits and power control systems used in switching power supply systems

Abstract

A drive circuit and power control system for use in a switching power supply system are disclosed. The switching power supply system includes a half-bridge structure, and the drive circuit is connected to the high-side power transistor of the half-bridge structure and includes: a detection module configured to generate an action signal for controlling the on / off state of the high-side power transistor based on a control signal, and to generate a detection signal indicating whether the control signal is abnormal, wherein the control signal is obtained based on the state of the high-side power transistor; and a drive module configured to determine the logic level of a drive signal for driving the high-side power transistor based on the action signal, and to control the voltage rise rate of the drive signal based on the logic level of the drive signal and the detection signal.

Claims

1. A drive circuit for use in a switching power supply system, the switching power supply system including a half-bridge structure, the drive circuit being connected to the high-side power transistor of the half-bridge structure and comprising: A detection module is configured to generate an action signal for controlling the on / off state of the high-side power transistor based on a control signal, and to generate a detection signal indicating whether the control signal is abnormal, wherein the control signal is obtained based on the state of the high-side power transistor; and a drive module is configured to determine the logic level of a drive signal for driving the high-side power transistor based on the action signal, and to control the voltage rise rate of the drive signal based on the logic level of the drive signal and the detection signal.

2. The driving circuit as described in claim 1, wherein, The drive module is further configured to control the magnitude of the pull-up current associated with the drive signal based on the logic level of the drive signal and the detection signal, so as to control the voltage rise rate of the drive signal.

3. The driving circuit as described in claim 2, wherein, The drive module is further configured to: determine the logic level of the drive signal as low when the action signal is invalid; determine the logic level of the drive signal as high and control the pull-up current to a first current when the action signal is valid and the detection signal indicates that the control signal is abnormal; and determine the logic level of the drive signal as high and control the pull-up current to a second current when the action signal is valid and the detection signal indicates that the control signal is normal, wherein the first current is less than the second current.

4. The driving circuit as described in claim 2, wherein, The drive module includes: a first component unit configured to output a first component current when the action signal is valid; and a second component unit configured to output a second component current when the action signal is valid and the detection signal indicates that the control signal is normal, wherein the pull-up current is the sum of the currents output by the first component unit and the second component unit.

5. The drive circuit as described in any one of claims 1 to 4, wherein, The control signal includes a set signal indicating that the high-side power transistor is turned on, and a reset signal indicating that the high-side power transistor is turned off. When the set signal and the reset signal are both valid, the detection signal indicates that the control signal is abnormal.

6. The driving circuit as described in claim 5, wherein, The detection module includes an inverse OR gate, the first input terminal and the second input terminal of the inverse OR gate respectively receive the set signal and the reset signal, and the output terminal of the inverse OR gate outputs the detection signal.

7. The drive circuit as described in claim 5, wherein, When the set signal changes from invalid to valid, the action signal changes from invalid to valid; when the reset signal changes from invalid to valid, the action signal changes from valid to invalid.

8. The driving circuit as claimed in claim 1, wherein, It also includes a boost module configured to boost the control signal to the voltage domain of the detection module.

9. A power control system for use in a switching power supply system, comprising a drive circuit as described in any one of claims 1 to 8.

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