초록 ▼

A current limit circuit for protection of an intelligent power switch includes a series circuit of a sense transistor and a sense resistor coupled to the power semiconductor transistor switch so that the sense resistor current is a fraction of, and is proportional to, the power transistor current. A

A current limit circuit for protection of an intelligent power switch includes a series circuit of a sense transistor and a sense resistor coupled to the power semiconductor transistor switch so that the sense resistor current is a fraction of, and is proportional to, the power transistor current. A pull-down transistor is coupled to the control electrode of the power transistor switch. A feedback circuit including a series connection of a diode-connected transistor and a reference V source is coupled between the sense resistor and the control electrode of the pull down transistor. The feedback circuit produces a voltage level shift and the circuit provides an accurate limit on the power transistor current independent of any variations in threshold voltage.

대표청구항 ▼

A current limit circuit comprising: first and second terminals for supplying an operating voltage to the current limit circuit, a power transistor, means for connecting said power transistor and a load in series to said first and second terminals, a sense transistor and a sense resistor connected in

A current limit circuit comprising: first and second terminals for supplying an operating voltage to the current limit circuit, a power transistor, means for connecting said power transistor and a load in series to said first and second terminals, a sense transistor and a sense resistor connected in a series circuit with the load to said first and second terminals such that a current flow through the sense resistor is proportional to a current flow through the power transistor, a further transistor connected between a control electrode of the power transistor and a point of reference potential, a feedback circuit connected between a junction point of the sense transistor and the sense resistor and a control electrode of the further transistor, said feedback circuit including a series connection of a semiconductor device and a reference voltage source providing a reference voltage which together produce a voltage level shift, and means for coupling the control electrode of the power transistor and a control electrode of the sense transistor to a signal input terminal of the current limit circuit.