Q
I would like to know the conversion method of the temperature measurement using
the internal temperature sensor in the AD7689.
I have measured the folowing data:
at -40 (cell) -> C73
at +80 (cel) -> 140C
Using ext Vref 4.096, 16 bit data out
Can you please tell me the conversion formula? (volts to temp)
A
The AD7689 temp sensor conversions are forced to be single-ended conversions
referenced to GND (unipolar) and are therefore straight binary. This temp
sensor output is typical (283 mV @ 25 ̊C) and not trimmed to be absolutely
accurate and hence not a guaranteed spec and it changes as the temp increases
of decreases. For 4.096V reference, the temp sensor output would be -
(4.096V/65536)*output code that you read from the ADC and it changes as the
temp increases of decreases.
