signal conditioning, error, range

[kovibb]

hi all,

I have this problem, or dilemma. Temperature sensor give me output signal in 2.606-0.835V in range (from 120C to -40C). I want to use 10 bit converter for example like this MAX1242/MAX1243. So, what i want to know is, what is different among when i come this input signal to A/D converter directly and when i use operational ampliefier with reference 0.835V and gain to get full A/D reference range? what is more precision? And I most interest to calculate error among them. Maybe some generous advices to help me.

Thanks

 

[godfreyl]

Using an opamp to get full A/D reference range will give better precision. With the direct connection, you lose about 1/3 of the range, but measurements will still be accurate to about 1/4 of a degree centigrade.