Standby power supply circuit
AssigneeHon Hai Precision Industry Co., Ltd.
InventorHo-Feng Lin
Life of this patent
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Abstract
A standby power supply circuit includes a pulse width modulation controller, first to fourth metal-oxide-semiconductor field effect transistors (MOSFETs), and an inductor. A gate of the first MOSFET and a gate of the second MOSFET are connected to a first and a second general purpose terminals of a power management chip, respectively. A drain of the first MOSFET is connected to a source of the third MOSFET. A gate of the fourth MOSFET is connected to a lower gate terminal of the controller. A phase terminal of the controller is grounded via the inductor and a capacitor in series. The drain of the second MOSFET is connected to a node between the inductor and the capacitor via a resistor.
Claims7
A standby power supply circuit, comprising:
- a pulse width modulation (PWM) controller comprising a power terminal, a ground terminal, a compensation terminal, a feed back terminal, a booting terminal, a phase terminal, an upper gate terminal, and a lower gate terminal, wherein the power terminal of the PWM controller is connected to a first power source, the feed back terminal is connected to the compensation terminal via a first capacitor, the ground terminal is grounded, the booting terminal is connected to the phase terminal via a second capacitor;
- a first metal-oxide-semiconductor field effect transistor (MOSFET), wherein a drain of the first MOSFET is connected to the feed back terminal of the PWM controller, a gate of the first MOSFET is connected to a first general purpose terminal of a power management chip, a source of the first MOSFET is grounded via a first resistor;
- a second MOSFET, wherein a drain of the second MOSFET is connected to the drain of the first MOSFET, a gate of the second MOSFET is connected to a second general purpose terminal of the power management chip, a source of the second MOSFET is grounded via a second resistor;
- a third MOSFET, wherein a drain of the third MOSFET is connected to a second power source, a gate of the third MOSFET is connected to the upper gate terminal of the PWM controller, a source of the third MOSFET is connected to the phase terminal of the PWM controller;
- a fourth MOSFET, wherein a drain of the fourth MOSFET is connected to the source of the third MOSFET, a gate of the fourth MOSFET is connected to the lower gate terminal of the PWM controller, a source of the fourth MOSFET is grounded;
- an inductor, wherein the phase terminal of the PWM controller is connected to a first terminal of a third capacitor via the inductor, a second terminal of the third capacitor is grounded, the drain of the second MOSFET is connected to a node between the inductor and the third capacitor via a third resistor, the node between the inductor and the third capacitor outputs a standby power.
Dependencies are inferred from the claim text.