Method and circuit for providing accurate voltage sensing for a power transistor, or the like

摘要

A circuit (10) is disclosed for enabling voltage to be sensed across a power transistor (12) of the type which has first and second active regions, such as source (85) and drain (76) regions of an MOS transistor (12), or emitter and collector regions of a bipolar transistor (42), in a semiconductor substrate (72), with the first region (76) located along a first lateral extent in the substrate (72) to have ends at terminal locations (D1,S1) of the first lateral extent and the second region located along a second lateral extent in the substrate (72) to have ends at terminal locations (D2,S2) of the second lateral extent. The circuit (10) includes a first conductive line (20) connected to the first region at said terminal locations (D1,D2) of the first lateral extent, and a first voltage sensing connection (22) to a midpoint of the first conductive line (20). A second conductive line (28) is connected to the second region at the terminal locations (S1,S2) of the second lateral extent, and a second voltage sensing connection is made to a midpoint (34) of the second conductive line (28). The conductive lines (20,28) may be, for example, metal, polysilicon, or other suitable material.