초록 ▼

A monolithic clamping circuit (10) and a method of protecting a semiconductor power transistor (14) from entering avalanche breakdown. The semiconductor power transistor (14) controls the switching of an inductor (16). The monolithic clamping circuit (10) causes energy stored in the inductor (16) to

A monolithic clamping circuit (10) and a method of protecting a semiconductor power transistor (14) from entering avalanche breakdown. The semiconductor power transistor (14) controls the switching of an inductor (16). The monolithic clamping circuit (10) causes energy stored in the inductor (16) to be dissipated in the semiconductor power transistor (14). A voltage sense circuit (18) provides a feedback signal to a selector circuit (12) in response to a voltage at a collector terminal of the semiconductor power transistor (14). The selector circuit (12) switches the semiconductor power transistor (14) to the conductive mode when the feedback signal indicates a high voltage at the collector terminal of the semiconductor power transistor (14). Dissipating the energy stored in the inductor (16) while operating in the conductive mode prevents the semiconductor power transistor (14) from entering avalanche breakdown.

대표청구항 ▼

[ We claim:] [1.] A monolithic clamping circuit, comprising:a transistor having a control electrode, a first current carrying electrode, and a second current carrying electrode;a voltage sense circuit having an input and an output, wherein the input is coupled to the second current carrying electrod

[ We claim:] [1.] A monolithic clamping circuit, comprising:a transistor having a control electrode, a first current carrying electrode, and a second current carrying electrode;a voltage sense circuit having an input and an output, wherein the input is coupled to the second current carrying electrode of the transistor; anda selector circuit having a first input coupled for receiving a signal, a second input coupled to the output of the voltage sense circuit, and an output coupled to the control electrode of the transistor, wherein the selector circuit includes,(a) a NOR gate having a first input, a second input, and an output, wherein the first input of the NOR gate serves as the first input of the selector circuit and the second input of the NOR gate serves as the second input of the selector circuit,(b) an inverter having an input and an output, wherein the input of the inverter is coupled to the output of the NOR gate, and(c) a push-pull driver circuit having a first input, a second input, and an output, wherein the first input is coupled to the output of the inverter, the second input is coupled to the output of the NOR gate, and the output of the push-pull driver circuit serves as the output of the selector circuit.