Patent Number: RE36,998

Title: Circuit for limiting the output voltage of a power transistor

Abstract: A circuit for limiting the output voltage from a power transistor connected in series with a resonant load between a voltage supply and a voltage reference, ground, is disclosed. The circuit includes a semiconductor junction element, in particular a diode of the SCR type, having an anode terminal connected to the voltage supply, a cathode terminal connected to a common circuit node between the power transistor and the resonant load, and a control terminal connected to a reference voltage of predetermined value. The reference voltage can be constructed by using a resistor connected in series with a diode across the voltage supply. The SCR diode is constructed using the parasitic PNP-NPN transistors which exist in the structure of the power transistor.

Inventors: Palara; Sergio (S.M. La Stella, IT)

Assignee: STMicroelectronics S.r.l.

International Classification: H03K 17/0814 (20060101); H03K 17/16 (20060101); H03K 17/08 (20060101); H03K 005/08 (); H03K 017/60 ()

Expiration Date: 12/26/2017