A 6.1-nW Wake-Up Receiver Achieving −80.5-dBm Sensitivity Via a Passive Pseudo-Balun Envelope Detector

Abstract

A wake-up receiver (WuRX) that achieves −80.5-dBm sensitivity with only 6.1 nW of power is presented. High sensitivity is achieved via a passive pseudo-balun envelope detector (ED) with a high input impedance ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$&gt; 750~\text {k}{\Omega }\;{\|}{&lt; }1.4$ </tex-math></inline-formula> pF) that enables a 30.6-dB passive voltage gain transformer while providing differential output and improving the conversion gain by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${2}{\times }$ </tex-math></inline-formula> compared to a conventional single-ended input passive ED for a given input capacitance. The WuRX is implemented in a 180-nm CMOS process and operates from a 0.4-V supply.