HIGH SIDE POWER SWITCH WITH CHARGE PUMP AND BOOTSTRAP CAPACITOR
First Claim
1. A power switching circuit comprising:
- a power semiconductor switching device;
a charge pump circuit having a control input to control whether the charge pump is on or off and a charge pump output, the charge pump output being coupled to a control terminal of the power semiconductor switching device;
a bootstrap power supply for supplying power to driver circuitry for the power semiconductor switching device, the bootstrap power supply comprising a bootstrap capacitor coupled to a charging current source;
the bootstrap power supply providing power to the driver circuitry when the power semiconductor switching device is being switched by the driver circuitry in a pulsed mode; and
the charge pump supplying a control voltage to turn on the power semiconductor switching device and maintain it on when the power switching device is to be maintained on continuously; and
wherein a transistor switch of the driver circuitry is actively controlled to prevent the charge pump from charging the bootstrap capacitor.
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Accused Products
Abstract
A power switching circuit comprising a power semiconductor switching device, a charge pump circuit having a control input to control whether it is on or off and a charge pump output, the charge pump output being coupled to a control terminal of the power semiconductor switching device, a bootstrap power supply for supplying power to driver circuitry for the power semiconductor switching device, the bootstrap power supply comprising a bootstrap capacitor coupled to a charging current source, the bootstrap power supply providing power to the driver circuitry when the power semiconductor switching device is being switched by the driver circuitry in a pulsed mode, and the charge pump supplying a control voltage to turn on the power semiconductor switching device and maintain it on when the power switching semiconductor device is to be maintained on continuously.
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Citations
10 Claims
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1. A power switching circuit comprising:
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a power semiconductor switching device;
a charge pump circuit having a control input to control whether the charge pump is on or off and a charge pump output, the charge pump output being coupled to a control terminal of the power semiconductor switching device;
a bootstrap power supply for supplying power to driver circuitry for the power semiconductor switching device, the bootstrap power supply comprising a bootstrap capacitor coupled to a charging current source;
the bootstrap power supply providing power to the driver circuitry when the power semiconductor switching device is being switched by the driver circuitry in a pulsed mode; and
the charge pump supplying a control voltage to turn on the power semiconductor switching device and maintain it on when the power switching device is to be maintained on continuously; and
wherein a transistor switch of the driver circuitry is actively controlled to prevent the charge pump from charging the bootstrap capacitor. - View Dependent Claims (2, 4, 5, 6, 7)
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3. (Canceled)
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8. (Canceled)
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9. A method for switching a power semiconductor, comprising:
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generating a voltage from a charge pump circuit having a control input to control whether the charge pump circuit is on or off and selective providing the voltage to a control terminal of the power semiconductor;
charging a bootstrap capacitor of a bootstrap power supply when the power semiconductor is being switched by the driver circuitry in a pulsed mode;
providing power to the driver circuitry from the bootstrap power supply when the power semiconductor is being switched by the driver circuitry in the pulsed mode; and
supplying a control voltage from the charge pump circuit to turn on the power semiconductor and maintain it on when the power semiconductor is to be maintained continuously; and
preventing charging of said bootstrap capacitor by said charge pump circuit by actively controlling a transistor switch of the driver circuitry.
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10. (Canceled)
Specification