INA229: Reverse Polarity Impact on INA229 Current Measurement IC

Hemil Gujarati

Part Number: INA229

Tool/software:

Hello,

I'm using the INA229 current measurement IC in my design. I would like to know what would happen if the main battery supply is connected with reverse polarity (VBAT and GND). Specifically, would the IC be damaged or would it cause incorrect measurements? Are there any built-in protections in the INA229 to handle reverse polarity, or should I add external components to protect it?

Thank you for your assistance!

over 1 year ago

0 Clemens Ladisch over 1 year ago

Guru 318700 points

Voltages lower than −0.3 V (relative to the INA229's GND) can damage the device.

Where does the 3V3 come from?

0 Hemil Gujarati over 1 year ago in reply to Clemens Ladisch

Prodigy 30 points

Thank you for reply. The 3V3 is coming from DCDC.

0 Clemens Ladisch over 1 year ago in reply to Hemil Gujarati

Guru 318700 points

From the battery, or from an independent supply?

Anyway, this does not change the absolute maximum ratings.

0 Hemil Gujarati over 1 year ago in reply to Clemens Ladisch

Prodigy 30 points

It is from the battery. So, now I have added reverse polarity protection for ground of INA. Still, The INA gets damage even if there is protection placed. With this protection, it won't reach absolute maximum ratings. Here, I have updated schematic.

0 Mitch M over 1 year ago in reply to Hemil Gujarati

TI__Mastermind 27420 points

Hey Hemil,

Clemens is correct that the device could be damaged if you exceed the device maximum ratings. Similar to this, the GND of the INA and VBAT need to be the same, otherwise the VCM max/min voltage spec could be violated with respect to device GND.

Regards,

Mitch

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INA229: Reverse Polarity Impact on INA229 Current Measurement IC