Temperature Sensing crystal
Temperature sensing crystal combines with a thermistor, making it sensitive to the temperature. IC will adjust the frequency change with temperature variations, getting temperature signal from the thermistor. Full size range for your choice, TSX 2520, 2016, 1612, with frequency of 19.2MHz, 26MHz, 38.4MHz, 76.8MHz certified by Qualcomm, MTK, ASR, etc.