Patent attributes
A block of phase change material located in a semiconductor chip is reset to an amorphous state. The block of phase change material may be connected to an internal resistance measurement circuit that can transmit the measured resistance data to input/output pads either in an analog output format or in a digital output format. Depending on the ambient temperature, the resistance of the block of phase change material changes. By measuring a fractional resistance change compared to the resistance of the phase change material at a calibration temperature, the temperature of the region around the phase change material can be accurately measured. A logic decoder and an input/output circuit may be employed between the internal resistance measurement circuit and the input/output pads. A plurality of temperature sensing circuits containing phase change material blocks may be employed in the semiconductor chip to enable an accurate temperature profiling during chip operation.