A full-scale CMOS voltage-to-frequency converter for WSN signal conditioning

This paper presents a low-cost CMOS voltage-to-frequency converter (VFC) with almost full-scale input operating range for front-end smart sensor interfaces in wireless sensor networks (WSN) applications. The proposed VFC, designed in a 0.35μm CMOS technology supplied at 3 V, is a cost-effective circuit, exhibiting at the same time high performance characteristics: it operates with a power consumption below 0.8 mW at output frequencies ranging from 0.1 MHz to 2.7 MHz with an error below 4 % given a 0.1-2.7 V input (1 MHz/V sensitivity).