A 346μm² reference-free sensor interface for highly constrained microsystems in 28nm CMOS

Abstract

A 346μm 2 reference-free, asynchronous VCO-based sensor interface circuit is demonstrated in 28nm LP CMOS. This design does not require high accuracy current sources, voltage sources, or low jitter timing references. It achieves wide resolution and voltage scalability, and consumes only ~1/100 th the area of prior approaches. Resolution can be scaled from 2.8 to 11.7 bits and V DD from 500mV to 1.0V.