A 20.5-nW Resistor-Less Bandgap Voltage Reference With Self-Biased Compensation for Process Variations
Youngwoo Ji, Jae‐Yoon Sim
Abstract
This brief proposes a resistor-less bandgap reference (BGR) based on a leakage-based proportional-to-absolute-temperature (PTAT) scheme. The effect of process variations on the current is mitigated by employing self-biased current-limiting MOS transistors. The bias voltages needed for approximating a large resistance can be obtained from a single branch by placing threshold-sampling transistors on top of the BGR output. The fabricated BGR in 0.18- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> CMOS occupies an active area of 0.035 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and consumes 20.5 nW, and it shows a standard deviation of 0.68% at untrimmed reference voltages.