INA181: INA181A2 solve some problem

Claudio Maria Lamacchia

Prodigy 100 points

Part Number: INA181
Other Parts Discussed in Thread: INA281,

Hi,

I’m using the INA181A2 as in the image below

On my board I have V+ = 11.78V and V-=11.76V, so the differential voltage is about 20mV.

Since the gain is 50V/V I expect 50*20mV = 1V, but I measure 2.05V.

I checked that the component is right (mark on IC is 1AED).

What should I do wrong?

Thank you in advance for your precious support.

over 3 years ago

0 Javier Contreras4 over 3 years ago

TI__Mastermind 30260 points

Hello Claudio,

Make sure you measure at the pins of the INA281. Check if there is a difference between what you see at the resistor and what voltage you see at the INA181 pins. I would use a meter that you can measure the differential so you are not doing a difference after the fact as this could lead to errors as well. If you see a difference you may have a layout issue.

Is there any switching going on?

I do not see any other big issues.

0 Javier Contreras4 over 3 years ago in reply to Javier Contreras4

TI__Mastermind 30260 points

Claudio,

I assume you found the root cause. Please post if you have further questions.

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INA181: INA181A2 solve some problem