A precision high-voltage current sensing circuit

Abstract

This paper presents a precision current sensor featuring a high voltage, high gain (~ 140 dB), and low input offset ( < 1 mV) current sense amplifier. This amplifier does not require offset trimming even for low offset applications. It is a single stage amplifier that has a common gate pMOS differential input pair, which makes it inherently stable. This amplifier topology allows for a wide input common-mode range, thus increasing the versatility of current sensing circuit.