US 2008/0164856 A1 · CURRENT SENSING CIRCUIT AND POWER SUPPLY USING THE SAME

Abstract

A current sensing circuit and power supply using the same are provided. The current sensing circuit includes a transistor, a control circuit and a sensing circuit, wherein the voltage endurance capability between a drain terminal of the transistor and a gate of the transistor is larger than the voltage endurance capability between a source terminal of the transistor and the gate of the transistor. The drain terminal is coupled to an under testing current source with an external high voltage. The control circuit is coupled to the gate of the transistor to control the conduction between the drain and the source terminals. The sensing circuit receives a sensing current signal from the source terminal of the transistor and transfers thereof to be a current sensing voltage.

Claims13

Dependent claims

A current sensing circuit, comprising:

a half high-voltage transistor, the voltage endurance capability between a drain terminal of the half high-voltage transistor and a gate of the half high-voltage transistor being larger than the voltage endurance capability between a source terminal of the half high-voltage transistor and the gate of the half high-voltage transistor, the drain terminal of the half high-voltage transistor being coupled to an under testing current source with an external high voltage;
a controlling circuit coupled to the gate of the half high-voltage transistor to control the conduction between the drain and the source terminals;
and
a sensing circuit receiving a sensing current signal from the source terminal of the half high-voltage transistor and transferring the sensing current signal to be a current sensing voltage.

1 more element

A power supply, comprising:

a magnetic element, an end of the magnetic element being coupled to an input voltage;
a half high-voltage transistor, the voltage endurance capability between a drain terminal of the half high-voltage transistor and a gate of the half high-voltage transistor being larger than the voltage endurance capability between a source terminal of the half high-voltage transistor and the gate of the half high-voltage transistor, the drain terminal of the half high-voltage being coupled to the other end of the magnetic element;
a controlling circuit coupled to the gate of the half high-voltage transistor to control the conduction between the drain and the source terminal;
and
a sensing circuit receiving a sensing current signal from the source terminal of the half high-voltage transistor and transferring the sensing current signal to be a current sensing voltage.

2 more elements

Dependencies are inferred from the claim text.

Current sensing circuit and power supply using the same

Life of this patent

Current sensing circuit and power supply using the same

Life of this patent

Abstract

Claims13