An 1 V Supply, 740 nW, 8.7 ppm/°C Bandgap Voltage Reference With Segmented Curvature Compensation

This paper presents a segmented curvature-compensated bandgap voltage reference (BGR) with low temperature coefficient (TC) and power consumption across a wide temperature range. In this work, we achieve temperature segmentation by comparing voltage instead of current, as in the conventional method, significantly reducing power consumption. Furthermore, we examine the trade-off between TC and power consumption, focusing on optimizing the number of temperature segments. In the core circuit, we utilize a regulated cascode current mirror to minimize channel length modulation induced error existing in the current-based BGR topology. We also introduce a replica structure to prevent oscillation and design comparators with the hysteresis characteristic to address noise influence. The proposed BGR, implemented in 65 nm CMOS, occupies an active area of 0.058 mm2. Measurement results of 6 chips show that the achieved reference voltage of 431.3 mV under 1 V supply has the best TC of 8.7 ppm/°C over a temperature range of −40 °C to 90 °C, consuming 740 nW at 20 °C.