INA821: Temperature Drift Coefficient

Uros Platise

Part Number: INA821

Hi,

in our application with INA821, G=10, sensing a thermocouple, we have measured a drift:

INA821 CH1: 12 ppm/K
INA821 CH2: 10.8 ppm/K

as per data-sheet (section 8.3.1.1) it specifies min gain drifft of 5 ppm/K, and the rest of contribution is due to external resistor relative to internal resistors.

Can we assume that in a lot of INA821 the gain drift will always be, for the same operation of INA821 at G=10:

positive (same direction)
of similar values (assuming the use of 5 ppm/K external gain resistor)

BR Uros

over 5 years ago

0 kai klaas69 over 5 years ago

Guru 140200 points

Hi Uros,

datasheet of INA821 specifies a maximum drift of +/-35ppm/K for G>1, excluding the effect of external gain setting resistor. Does this answer your questions?

Kai

0 Uros Platise over 5 years ago in reply to kai klaas69

Prodigy 135 points

This I could see, my questions were more specific, for given operational point, if it is possible to obtain more specific information about the nature (sign) of drift for same conditions of operation.

BR Uros

0 kai klaas69 over 5 years ago in reply to Uros Platise

Guru 140200 points

Hi Uros,

the nature of drift is slight imbalance of internal circuitry. This explains the "+" and the "-" in the +/-35ppm/K specification of INA821.

Kai

0 Dennis Goeke over 5 years ago in reply to kai klaas69

TI__Genius 11135 points

Uros

We have not heard back from you so we will close this thread. Please reply if further discussion is needed.

Thanks
Dennis

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INA821: Temperature Drift Coefficient