Dear Sir/Madam,
We are using the TMP20AIDRLR on our board as the temperature sensor. The ADC that we connected with this sensor is MCP3208-CI/SL. However, we got some questions with this sensor. When measuring the output pin with multimeter, it shows 1.544V. But the translated voltage read out by ADC is 1.76V. TMP20 output seems to be very sensitive to the loading. By checking its datasheet(Section 8.1), we just found that we didn't put the filter cap between the TMP20 and the ADC.
However, the datasheet didn't give an exact recommended value for this filter cap. We tried to put a 120pF cap. Then the ADC readout become similar with the result that measured by multimeter. But we are afraid that adding 120pF might not be the optimal solution. Could you please give us some suggestions on this capacitor value's selection?
Thank you very much!
Best,
Mengqi
