A 139 nW, 67 $$\hbox {ppm}/^\circ \hbox {C}$$ ppm / ∘ C BJT-CMOS-Based Voltage Reference Circuit

Abstract

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 \(0.18\,\upmu \hbox {m}\) standard CMOS technology for the industrial temperature range of \(-40\) to \(+85\,^\circ \hbox {C}\). 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 \(115.4\,\hbox {nA}\), respectively, at \(22.5\,^\circ \hbox {C}\). The measured mean reference voltage obtained from the circuit is 435 mV with the mean temperature coefficient of \(67\,\hbox {ppm}{/}^\circ \hbox {C}\) . The measured noise density at \(22.5\,^\circ \hbox {C}\) without any filtering capacitor is \(42\,\upmu \hbox {V}{/}\sqrt{\text {Hz}}\) at 100 Hz. The active area of the circuit is \(0.01008\,\hbox {mm}^2\).