Patent ID: 9461639
Filing Date: 2016-10-04
CPC Classification: G05F,H01L,H02M,H03K

Claim Text:
1. A semiconductor device comprising a power transistor and a sense transistor, wherein the power transistor is arranged to conduct a power transistor current; the sense transistor is arranged to conduct a sense transistor current that is substantially proportional to the power transistor current; each of the power transistor and the sense transistor is a metal-oxide semiconductor field effect transistor, MOSFET, having a drain terminal, a source terminal, and a gate terminal; the drain terminal, the source terminal, and the gate terminal of the sense transistor are arranged to be biased to the drain potential, the source potential, and the gate potential of the power transistor, respectively; wherein the power transistor and the sense transistor each comprise: an inner region of type P−; an N-type buried layer; an N-type isolating barrier, the isolating barrier surrounding the inner region at least partially; an N-type source region in the inner region; an N-type drain region in the inner region; and a barrier-to-drain connector which connects the isolating barrier to the drain region; wherein the barrier-to-drain connector of the sense transistor has an electrical resistance which is higher than the resistance of the barrier-to-drain connector of the power transistor.