INA226: The monitored current has a slight deviation of a few mA

Lumina Gui

Part Number: INA226

Tool/software:

Dear TI Engineer,

We use INA226 to monitor the current and found that there is data even when there is no current passing through (no power supply in IN+), with values ranging from a few mA, and the value is constantly changing. When measuring high currents such as 1A, 2A, 3A, there may be a deviation of 1-3mA.

The schematic is as below:

We want to confirm if this iuuse is normal, and how to eliminate it in practical use?

Thanks,

Kind Regards

2 months ago

0 Mitch M 2 months ago

TI__Mastermind 26205 points

Hello Lumina,

It sounds like there is some noise on your system. If you would like to get a more clean measurement, then you will want to increase the conversion time and/or averaging of the INA226. It could also help to track down the source of the noise, for example, it could be coming from your supply or ground.

Here is a link to our TIPL video series that has a section on errors. You may be interested in the Power Supply Rejection or Common Mode Rejection Ratio error videos (or others).

https://www.ti.com/video/series/precision-labs/ti-precision-labs-current-sense-amplifiers.html

Regards,

Mitch

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INA226: The monitored current has a slight deviation of a few mA