A low power compact CMOS programmable temperature switch with process compensation

A low power compact CMOS programmable temperature switch with process compensation is presented. Its threshold temperature Tth can be programmed by a digital signal. The operating principle of the temperature switch is theoretically explained. We adopt a simple circuit architecture and a subthreshold CMOS circuit technique to reduce the chip size and the power consumption. A process compensation circuit is designed to compensate the threshold temperature Tth variation automatically. The switch circuit is implemented in a standard 0.18um CMOS process. The measured results show that the temperature switch can be programmed to perform the switch operation at 12 different threshold temperature Tths from 45°C–100°C with a 5°C increment. The chip core area is 0.03mm2 and the power consumption is less than 1uA at 1.8V power supply.