Design of ultra-low power CMOS temperature sensor ic with wake-up function

Abstract

This thesis describes the design of an ultra-low power CMOS temperature sensor IC with wake-up function intended for temperature sensing in building management system (BMS). The temperature sensor used in building management system (BMS) should provide an ultra-low power consumption because of their limited power available. To meet the condition, the proposed temperature sensor operates in asynchronous manner. The sensor with two-point calibration achieves a simulated inaccuracy of +2.34°C /-1.95°C and also shows excellent linearity over the temperature range from 0°C to 100°C. Most of all, the sensor with wake-up cell only dissipates the power below 1μW at the frequency of temperature variation under 1kHz. Especially, the simulated power consumption is only 228nW at the frequency of temperature variation of 6.9 Hz. In our daily life, especially in buildings, indoor temperature is almost always constant and the abrupt change of temperature is hardly probable. Therefore, the proposed sensor works to consume its minimum power of 228nW. In virtue of the asynchronous operation, the temperature sensors used in BMS applications dissipate their minimum power in most cases, but also immediately respond to a sudden variation of temperature.