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I'm designing a microcontroller-based system that includes a thermostat.

When choosing which temperature sensor to use, I noticed that analog ones have more or less the same power consumption, the same temperature range and the same cost as digital ones.

Aside from possibly having a higher resolution ADC on the MCU than the one included in the digital sensor chip, are there any advantages in using an analog temperature sensor over a digital one?

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    \$\begingroup\$ A thermocouple will operate at massively higher temperatures than silicon would ever survive. \$\endgroup\$
    – Andy aka
    Apr 25, 2016 at 9:43
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    \$\begingroup\$ A thermocouple will also operate at massively lower temperatures than the silicon would ever hope to operate (T, E or K types). \$\endgroup\$
    – Michael Karas
    Apr 25, 2016 at 9:50
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    \$\begingroup\$ Get a datasheet for a typical example of either type of temperature sensor. Then compare and see that above two comments are true. \$\endgroup\$
    – Bimpelrekkie
    Apr 25, 2016 at 9:58
  • \$\begingroup\$ The price of sensor itself maybe quite the same, but what about analog front end and ADC? \$\endgroup\$
    – Marko Buršič
    Apr 25, 2016 at 10:40
  • \$\begingroup\$ A Ge RTD will operate accurately at lower temperatures than any digital sensor (or thermocouple) will. \$\endgroup\$
    – Spehro Pefhany
    Apr 25, 2016 at 13:36

1 Answer 1

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Analog temperature sensors are easier in general to attach to the end of wires to make a temperature probe. On the other hand digital temperature sensors are in IC packages that are generally designed to be placed on a circuit board. This means that the probe type of sensor till typically have less thermal mass and be easier to couple to the medium being measured. A digital type IC sensor can be mounted on a small probe board on the end of a cable but it has more thermal mass and the IC package material does isolate the sensor some from the measured medium.

There are some digital IC temperature sensors that you can put on your MCU board but then support the attachment of a diode used as a temperature sensor. The diode is much easier to remote as a probe if that is needed. The ADT7476 is one example of this type of sensor.

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