Patent ID: 9551742
Date: 2017-01-24
CPC Classifications: G01R,H01L,H03K

Claim:
1. An overcurrent detection circuit for a power switch, the overcurrent detection circuit comprising a sampling circuit operatively coupled to the power switch and a comparing circuit operatively coupled to the sampling circuit; wherein the sampling circuit includes: a sampling Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) operatively coupled to the power switch, wherein the sampling MOSFET is configured to sample current in the power switch to generate a sampled current; an amplifier circuit having inputs operatively coupled to the sampling MOSFET and the power switch, the amplifier circuit including an amplifier output circuit having an operating voltage, wherein the sampling MOSFET and the amplifier circuit are configured to convert the sampled current into a sampled voltage and provide the sampled voltage to the comparing circuit; and a clamping MOSFET operatively coupled in series with the sampling MOSFET and configured to clamp the operating voltage of the amplifier output circuit and an operating voltage of the comparing circuit; and wherein the comparing circuit is configured to compare the sampled voltage with a reference voltage, and to output a result of overcurrent detection according to the comparing.