38.4-pW, 0.14-mm2 Body-Driven Temperature-to-Digital Converter and Voltage Reference with 0.6-1.6-V Unregulated Supply for Battery-Less Systems

A temperature-to-digital converter for low-cost purely-harvested systems is introduced. Its architecture is based on an oscillator pair with PTAT and CTAT frequency via body-driven control, and compact temperature sensors with implicit self-regulation. Supply regulation is eliminated for true sub100 pW power. State-of-the-art power of 38.4 pW is achieved in 180 nm at 0.6 V with 0.49-°C resolution at 0.14-mm
²
area.