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

Abstract

A 346μm2 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 ~1/100th the area of prior approaches. Resolution can be scaled from 2.8 to 11.7 bits and VDD from 500mV to 1.0V.