12-b Enhanced Input Range On-Chip Quasi-Digital Converter With Temperature Compensation

This brief presents a monolithic 1.8-V 0.18-μm CMOS temperature-compensated voltage-to-frequency converter for sensor read-out interfaces in wireless sensor network applications. Measurement results show that the proposed converter features are suitable for an output frequency span of 2 MHz with an input voltage range of 0.1-1.6 V. This converter presents a relative error below 4.8% and a linearity error below 0.017% (i.e., 12 b) over the whole frequency span for a range of ( -40°C, + 85°C). Power consumption is 0.423 mW (20 nW in sleep mode), and it occupies an active area of 137 μm x 100 μm.