INA180-Q1: Error and calibration

Oscar Liborio

Intellectual 930 points

Part Number: INA180-Q1
Other Parts Discussed in Thread: INA180

Tool/software:

Hi,

My customer has a few questions on the INA180-Q1

Under what condition is gain error is 500uV ?

If we do calibration which errors can be eliminated/reduced (please provide values) ?

Is the 1% Gain error mentioned in datasheet 6 sigma or 3 sigma ?

Oscar

3 months ago

0 Mallika Senthil 3 months ago

TI__Expert 7020 points

Hi Oscar,

I'm not sure where you see 500uV gain error in our datasheet, at a Vs = 5V and Vin+ = 12V, we spec max Eg = +/- 1%.

The INA180 has a max offset voltage rating of 500uV, this depends on the shunt value and the input voltage. Please refer to the following TI video for more information on voltage offset. https://www.ti.com/video/6096850535001

I recommend using our error calculator to find the optimum conditions (temperature, shunt resistor) to minimize errors: https://www.ti.com/tool/CS-AMPLIFIER-ERROR-TOOL

Best,
Mallika Senthil

0 Oscar Liborio 3 months ago in reply to Mallika Senthil

TI__Intellectual 930 points

Hi Malika,

Sorry I actually meant 500 uV of offset voltage. From the datasheet it seems that this is the max offset voltage for a CMV of 12V. Would it be higher for higher CMV?

Thank you for sharing the tool. Is there also a paper explaining which part of the error can be virtually removed by calibration?

Also, what is the value of the sigma (standard deviation) for the Gain error?

Thank you!

Oscar

0 Mallika Senthil 3 months ago in reply to Oscar Liborio

TI__Expert 7020 points

Hi Oscar,

Oscar Liborio said:
Thank you for sharing the tool. Is there also a paper explaining which part of the error can be virtually removed by calibration?

The following set of presentations and App notes should help you:

https://www.ti.com/lit/ug/slya042/slya042.pdf

https://www.ti.com/content/dam/videos/external-videos/en-us/4/3816841626001/6118346755001.mp4/subassets/current-sense-amplifiers-shunt-resistor-tolerance-error-presentation-quiz.pdf

https://www.ti.com/content/dam/videos/external-videos/en-us/4/3816841626001/6117678391001.mp4/subassets/current-sense-amplifiers-gain-error-presentation-quiz.pdf

Oscar Liborio said:
Sorry I actually meant 500 uV of offset voltage. From the datasheet it seems that this is the max offset voltage for a CMV of 12V. Would it be higher for higher CMV?

Yes it would be slightly higher as Vcm exceeds 12V. Please note we don't spec offset data beyond Vcm = 12V.

Oscar Liborio said:
Also, what is the value of the sigma (standard deviation) for the Gain error?

The Figures 7.11 to 7.14 in the datasheet show the gain error distribution, I believe the standard deviation is 3 sigma.

Best,
Mallika Senthil

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INA180-Q1: Error and calibration