INA790A: Resistor temperature drift chart

LIU QINGFENG

Prodigy 80 points

Part Number: INA790A
Other Parts Discussed in Thread: INA791A, , INA254, INA791

Tool/software:

Hi, Expert:

I am looking for accurate method to sense 40A DC current and sounds INA254/INA790A/INA791A are good candidates.

From spec INA790A/INA791A are much better on the CMRR, gain error and so on...

However I can find sensing resistor temperature drift showing as blow in INA254 datasheet, which gives us high confidence that after calibration, accuracy could be guaranteed from 25C to 100C;

Is there similar data for INA790A/INA791A？

Qingfeng liu

6 months ago

0 LIU QINGFENG 6 months ago

Prodigy 80 points

I see there is package resistance vs temperature curve...

How this to do with sensing resistor ? if things were linear, I am sure there will be inner temperature senor and compensation has been made in the OPA output?

0 Guang Zhou 6 months ago in reply to LIU QINGFENG

TI__Mastermind 36040 points

Hi,

Temperature compensation is built into INA790 and INA791 to achieve low overall drift. The datasheet alluded to this.

Regards

Guang

0 LIU QINGFENG 6 months ago in reply to Guang Zhou

Prodigy 80 points

Good to know there is built-in compensation, could there be similar curve to show the sensing resistor temperature drift, as INA254 to tell how flat the resistor values is in the useful temperature range (from room temperature to 100degC）.

+1 Guang Zhou 6 months ago in reply to LIU QINGFENG

TI__Mastermind 36040 points

Hi,

The shunt is part of the leadframe. Therefore the tempCo is similar to that shown in Figure 6-1.

In INA254, the integrated shunt has to be flat because there is no temperature compensation.

Regards

Guang

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INA790A: Resistor temperature drift chart