A Resistor-Compensation Technique for CMOS Bandgap and Current Reference with Simplified Start-Up Circuit

Abstract

This paper presents a resistor-compensation technique for a CMOS bandgap and current reference, which utilizes various high positive temperature coefficient (TC) resistors, a two-stage operational transconductance amplifier (OTA) and a simplified start-up circuit in the 0.35-µm CMOS process. In the proposed bandgap and current reference, numerous compensated resistors, which have a high positive temperature coefficient (TC), are added to the parasitic n-p-n and p-n-p bipolar junction transistor devices, to generate a temperature-independent voltage reference and current reference. The measurements verify a current reference of 735.6nA, the voltage reference of 888.1mV, and the power consumption of 91.28µW at a supply voltage of 3.3V. The voltage TC is 49ppm/°C in the temperature range from 0°C to 100°C and 12.8ppm/°C from 30°C to 100°C. The current TC is 119.2ppm/°C at temperatures of 0°C to 100°C. Measurement results also demonstrate a stable voltage reference at high temperature (> 30°C), and a constant current reference at low temperature (< 70°C).