SBAA274A September 2018 – March 2023 ADS1118 , ADS1119 , ADS1120 , ADS112C04 , ADS112U04 , ADS1146 , ADS1147 , ADS1148 , ADS114S06 , ADS114S06B , ADS114S08 , ADS114S08B , ADS1219 , ADS1220 , ADS122C04 , ADS122U04 , ADS1246 , ADS1247 , ADS1248 , ADS124S06 , ADS124S08 , ADS125H02 , ADS1260 , ADS1261 , ADS1262 , ADS1263
Many semiconductor temperature sensors have temperature measurement accuracies below 1°C and can be used for cold-junction compensation. Figure 2-13 shows a circuit that uses the LMT70 for measurement.
The measurement circuit requires:
This ADC measurement is a directly measures voltage and requires a known reference voltage. The output of the LMT70 gives an output voltage that can be used to calculate a temperature. Table 2-1 shows voltages that can be used to convert the LMT70 output to temperature.
One important consideration for this measurement is the input range of the PGA. The output of the LMT70 extends to the ground node and an accurate temperature measurement of the temperature may not be possible unless the PGA is disabled. Consult the ADC data sheet for PGA specifications and operation.
For more information about the LMT70, consult LMT70, LMT70A ±0.05°C Precision Analog Temperature Sensor, RTD and Precision NTC Thermistor IC.