Temperature sensor applications of diode-connected MOS transistors

The transconductance characteristics of a MOS transistor realized in a submicron technology have the zero-temperature coefficient (ZTC) bias point. The gate-source voltage of such transistor is linearly dependent on temperature when the transistor is diode-connected and biased by a current source. The slope of the dependence is related to the bias current value, and can be positive, negative or zero. Hence, the diode-connected transistor can be used as a controllable temperature sensor. This conclusion was experimentally verified using a circuit designed for 0.18 /spl mu/m CMOS technology.