Methods and apparatus for sensing current through power semiconductor devices with reduced sensitivity to temperature and process variations

• Main Authors: Chandrasekaran Ramesh, Kaya Cetin
• Format: Patent
• Language: English
• Published: 22.08.2017
• Subjects: BASIC ELECTRONIC CIRCUITRY; ELECTRICITY; PULSE TECHNIQUE

Current sensing through a power semiconductor device with reduced sensitivity to temperature and process variations. An example arrangement includes a power switch coupled between a voltage input and an output voltage terminal supplying current to a load; a first isolation switch coupled between the voltage input and a first node; a comparator amplifier having a pair of differential inputs coupled to the first node and a second node outputting a voltage in response to the difference at the differential inputs; and a first current source coupled between a positive supply voltage and the first node to output a first current responsive to the voltage output from the comparator amplifier; wherein the first current is proportional to the current through the power switch and a ratio of the on resistance of the power switch and the on resistance of the first isolation switch. Methods and additional arrangements are also disclosed.