US 7,598,627 B2 · Switch-mode power supply

Abstract

A switch-mode power supply for selectively providing power from a main power source and a standby power source to an electronic device is provided. The switch-mode power supply includes a signal input, a first transistor, a second transistor, a driving circuit, and a switching circuit. The signal input is used for receiving a control signal. The driving circuit and switching circuit connect the signal input to the gate of the second transistor in series. When the driving circuit detects the first transistor is switched off, the gate of the second transistor is immediately pulled up to open the second transistor, and when the driving circuit detects the first transistor is switched on, the gate of the second transistor is immediately pulled down to close the second transistor.

Claims12

Dependent claims

A switch-mode power supply for selectively providing power from a main power source and a standby power source to an electronic device, comprising:

a signal input for receiving a control signal;
a first transistor having a gate connected to the signal input for receiving the control signal, a drain acting as a voltage output, and a source connected to the standby power source;
a second transistor having a gate, a drain acting as the voltage output, and a source connected to the main power source;
a driving circuit and a switching circuit connected between the signal input and the gate of the second transistor in parallel such that when the driving circuit detects the first transistor is switched off, the gate of the second transistor is immediately pulled up to open the second transistor by the switching circuit, and when the driving circuit detects the first transistor is switched on, the gate of the second transistor is immediately pulled down by the driving circuit to close the second transistor.

1 more element

A switch-mode power supply, comprising:

a signal input for receiving a control signal;
a first transistor having a gate connected to the signal input, a drain acting as a voltage output, and a source connected to a standby power source;
a second transistor having a gate, a drain acting as the voltage output, and a source connected to a main power source;
a driving circuit connecting the signal input to the gate of the second transistor;
a switching circuit connecting the signal input to the gate of the second transistor;
wherein when the driving circuit detects the first transistor is switched off, the gate of the second transistor is immediately pulled up to open the second transistor by the switching circuit and the voltage output outputs a main voltage from the main power source, and when the driving circuit detects the first transistor is switched on, the gate of the second transistor is immediately pulled down by the driving circuit to close the second transistor and the voltage output outputs a standby voltage from the standby power source.

3 more elements

Dependencies are inferred from the claim text.

Switch-mode power supply

Life of this patent

Switch-mode power supply

Life of this patent

Abstract

Claims12