I am trying to build a low-power system. One of the system parts is a Temperature sensing circuit (0 <T<60 C). Since I am have limited power (~500 uA 3V). I was lost as to which approach is the best in terms of less power consumption.
[high Accuracy and fast sampling are not necessary]
Types I am looking at:
Which one have usually better for low power application? and do you recommend a certain model?
There are various way to approach the problem… an NTC/PTC has obviously as load its value at the temperature of interest (usually around 10kohms but even more depending on the model)
Active temperature sensors vary wildly: the almost overused LM35 needs about 100µA to work and gives an analog voltage, the TMP05 has a 600µA active mode but can be put in standby at some 10µA (output is a pulse duration by the way).
And now the most important trick of all: just power off the sensor when you don't need it. Even a PT100 RTD (which is a 100 ohm resistor, more or less) consume almost no power if you power it up only, say, every 5 seconds (depending on the application)
