A low power-integrated temperature sensor interface circuit

This paper constructs and simulates the interface circuit of a temperature sensor based on SMIC 0.18 mu m CMOS. The simulation results show that when the power supply voltage is 1.8 V, the chopper op-amp gain is 89.44 dB, the low-frequency noise is 71.83 nV/Hz,(1/2) and the temperature coefficient of the core temperature sensitive circuit is 1.7808 mV/degrees C. The sampling rate of 10-bit SAR ADC was 10 kS/s, effective bit was 9.0119, SNR was 59.3256 dB, SFDR was 68.7091 dB, and THD was -62.5859 dB. The measurement range of temperature sensor interface circuit is -50 degrees C similar to +125 degrees C, the relative temperature measurement error is +/- 0.47 degrees C, the resolution is 0.2 degrees C/LSB, and the overall average power consumption is 434.9 mu W.