The temperature sensor is one of the most important components of the cooled infrared detector assembly which measures and controls the operating temperature of the detector. Its working temperate directly affects the performance of the detector, such as SNR, detectivity and blind pixel rate. Considering that traditional PN junction temperature sensor requires complex analog signal processing and is easily affected by electromagnetic interference, a CMOS integrated digital temperature sensor was proposed. Fabricated in a 0.35 μm CMOS process, the chip area of the sensor is 380 μm×500 μm(without PAD), the proposed sensor reached the conversion speed of 6.1 times/s and consumed 300 μW when the working voltage is 2.5 V. The resolution of the sensor was 0.061 6 K and RMS noise is 0.148 K@77 K. The mesurement results prove that the proposed integrated digital temperature sensor is suitable for cooled infrared detector temperature measurement.