INA231: Can it support bidirectional usage at both high side and low side?

Yuan Lean

Prodigy 20 points

Part Number: INA231
Other Parts Discussed in Thread: INA232

INA231 was claimed that it is a bidirectional part. Can it support bidirectional current at low side?

8 months ago

0 Clemens Ladisch 8 months ago

Guru 263650 points

"Bidirectional" means that it can measure current flowing in the opposite direction, i.e., IN+ having a lower voltage than IN−. This is supported for both high-side and low-side configurations, over the entire common-mode voltage range.

0 Mitch M 8 months ago in reply to Clemens Ladisch

TI__Mastermind 19865 points

Thanks Clemens!

Yuan,

Let me know if you have any further questions.

Regards,

Mitch

0 Yuan Lean 8 months ago in reply to Clemens Ladisch

Prodigy 20 points

But the typical applicaiton is connect IN- and GND together at low side use. IN+ voltage will be negative if current flow from IN- to IN+. Doesn't this exceed common voltage spec?

+1 Clemens Ladisch 8 months ago in reply to Yuan Lean

Guru 263650 points

Yes, that would be outside the common-mode voltage range.

You could connect the INA231's GND to a lower voltage. Or use some other device (e.g., INA232) that can go down to −0.3 V (if this is enough). Or combine a difference amplifier with an ADC.

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INA231: Can it support bidirectional usage at both high side and low side?