A 139 nW, 67 ppm/°C BJT-CMOS-Based Voltage Reference Circuit

In this work, a low-power voltage reference circuit has been developed using the principle that a thermal compensation of the threshold voltage of a diode-connected nMOSFET can be obtained by using the PTAT current. The proposed circuit is designed using 0.18 mu m standard CMOS technology for the industrial temperature range of -40 to +85 degrees C. The measurements have been done over a set of 10 samples in the given temperature range. The measured results show that the proposed circuit is capable of working in the supply voltage range of 1.2-1.8 V with the mean line sensitivity and total current consumption of 0.64%/V and 115.4 nA, respectively, at 22.5 degrees C. The measured mean reference voltage obtained from the circuit is 435 mV with the mean temperature coefficient of 67 ppm/degrees C. The measured noise density at 22.5 degrees C without any filtering capacitor is 42 mu V/root Hz at 100 Hz. The active area of the circuit is 0.01008 mm(2).