A HIGHLY LINEAR SINGLE P-N-JUNCTION TEMPERATURE SENSOR

A temperature sensor based on the use of two forward-biased p-n juncti ons is known to exhibit good linearity. An alternative sensor configur ation, based on the same principle, but employing only one p-n junctio n is presented in this paper. The forward current through the p-n junc tion is switched alternately between two fixed values, and the differe nce between the corresponding voltages is shown to vary linearly with temperature. This scheme eliminates the problems associated with close matching required for the two p-n junction sensors. Experimental resu lts obtained with the proposed scheme are presented. A configuration t o exploit the temperature dependence of the p-n junction incremental r esistance is also presented.