A 65-nm CMOS Constant Current Source With Reduced PVT Variation

This paper presents a new nanometer-based low-power constant current reference that attains a small value in the total process-voltage-temperature variation. The circuit architecture is based on the embodiment of a process-tolerant bias current circuit and a scaled process-tracking bias voltage source for the dedicated temperature-compensated voltage-to-current conversion in a preregulator loop. Fabricated in a UMC 65-nm CMOS process, it consumes 7.18 μW with a 1.4 V supply. The measured results indicate that the current reference achieves an average temperature coefficient of 119 ppm/°C over 12 samples in a temperature range from -30 °C to 90 °C without any calibration. Besides, a low line sensitivity of 180 ppm/V is obtained. This paper offers a better sensitivity figure of merit with respect to the reported representative counterparts.