offset of sensor & offset of IA

[fxxjssc]

hi all,
I am designing a temp sensor circuit. My stucture is sensor+IA+ADC.
you know, offsets exist both in sensor and IA. what's the relationship between
offset of sensor and offset of IA? why?
in some paper, offset of sensor is smaller than offset of IA is needed.
would you give some sense?
best regards
jason

 

[amxu77]

the sensor offset is independent of IA offset. what we really care is the input referred offset, that is, all the offset, referred back to the sensor input.

if sensor has some gain, IA offset can be larger than sensor offset, bcz IA offset will attenuated by the sensor gain when referred back to sensor input. just like what happens in preamp and latch in a comparator.

hope this helps.