A High Performance Reference Circuit with Optimized Input Offset Operational Amplifier using Device Mismatch Model

Abstract

In this paper, author describes a band gap reference (BGR) circuit, having reference voltage 1.20V with maximum temperature coefficient of 63 ppm/⁰C in temperature range of –40 to 120 ⁰C. The circuit operates in range of supply voltage, 3.0V to 3.6V. An operational amplifier (op-amp), whose input offset voltage is reduced upto 892 µV using Pelgrom’s device mismatch model is used in BGR. The power supply rejection ratio of circuit is improved at higher frequency and achieved 36 dB at 1 MHz. The circuit having area of 0.45 mm² in 0.35 µm CMOS technology is designed, fabricated and tested successfully.

Keywords: CMOS bandgap reference, MOSFET mismatch modeling, operational amplifier, input offset voltage