Sub-1 V supply 5 nW 11 ppm/°C resistorless sub-bandgap voltage reference

In this work a resistorless sub-bandgap voltage reference topology is presented. It is a self-biased and small area circuit that works in the nano-ampere consumption range, and under 1 V of power supply. The behavior of the circuit is analytically described, a design methodology is proposed and simulation results are presented for two CMOS processes, XFAB 0.18 μm and IBM 0.13 μm. Experimental results from one fabrication run demonstrate a reference voltage of 570 mV, with a temperature coefficient as low as 11 ppm/°C for the 0–125 °C range, while the power consumption of the whole circuit is 5 nW under a 0.9 V supply at 27 °C. The occupied silicon area is 0.0022 mm2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^2$$\end{document}.