Improved supply regulation and temperature compensated current reference circuit with low process variations

This work presents a design of temperature compensated and supply regulated current reference circuit with reduced process variation at low supply voltage of 1.5 V. The supply regulation of the proposed circuit is improved by using a regulated cascode technique together with an error amplifier in the CTAT (complementary to absolute temperature) circuit. The temperature compensation is achieved by summing a PTAT (proportional to absolute temperature) and a CTAT current. The circuit can be properly operated at low supply voltages down to 1.2 V. The circuit is designed to provide 10 μA reference current. The temperature coefficient of 83.21 ppm/°C for a temperature range of -20°C to 120°C and a line-regulation of 673 ppm/V for a supply variation from 1.5 V-2.5 V is achieved at nominal process and temperature conditions in 180nm CMOS process. The total power consumption is 186 μW at 1.5 V supply.