A low-voltage bandgap reference with resistive subdivision

In this paper, a sub IV bandgap voltage reference (BGR) with resistive subdivision in CMOS technology is described. The proposed topology is based on the combination of two elements' voltages of opposite temperature coefficients. By using resistive subdivision methods, maximum input voltage of a p-channel input operational amplifier can be reduced and the problem of sub IV supply voltage is solved without complex low supply voltage amplifier. Inserting a capacitance Cc to ground at VREF can result in an improvement in power supply rejection ratio. The proposed circuit was verified by spectre simulations, using standard 0.25 mum CMOS process, and the results show that the presented bandgap reference can successfully operate at sub IV supply and has a temperature coefficient of 25ppm/degC over a temperature range from 0degC to 100degC. The power supply rejection ratio (PSRR) is high at low frequencies, and an added Cc is helpful for PSRR at high frequencies