Ultra low power, harsh environment SOI-CMOS design of temperature sensor based threshold detection and wake-up IC

An ultra-low-power temperature-sensor-based silicon-on-insulator (SOI) CMOS Integrated Circuit (IC) for harsh environment application is presented. It first detects a temperature threshold, secondly generates a wake-up signal that turns on a data-acquisition microprocessor once the threshold has been detected and thirdly operates as a temperature sensor in a harsh environment while being wired to the microprocessor kept in a safe area. The IC is continuously on for a very long period of time and is required to be powered from a ultrathin battery type, hence must be an ultra low power design. It includes a diode-based temperature sensor, a quasi-temperature independent voltage generator, a comparator and a power switch to limit the microprocessor stand-by consumption. Since our application is mainly for harsh environment (e.g. high temperature, radiation), the chip has been designed using the 1-µm high-temperature SOI-CMOS XFAB technology; it occupies an area of 560µm×165µm. The biasing current and power dissipation are 4.12 µA and 20.6 µW respectively at a supply voltage of 5V and temperature of 27°C, according to the post-layout transistor level simulation results.