Design of a 0.8V low power CMOS temperature sensor for RFID-based train axle temperature measurement

A novel CMOS temperature sensor embedded in a passive UHF RFID tag is presented. The sensor consists of a temperature-to-current converter, two current-starved ring oscillators and two digital counters. High power consumption band-gap voltage references and traditional ADCs are not used for low power design. Post-layout simulation show that the power consumption is 0.64 μW with a supply voltage of 0.8 V at room temperature (27°C), and the conversion rate is up to 1 kHz. The average temperature resolution is 0.2°C/LSB from -40°Cr~120°C. The sensor is implemented in CMOS 0.18 μm and the core occupies an area of 0.09 mm
²
.