INA216: How to recognize the current-sensing circuit's current direction/polarity?

Kevin Wong

Part Number: INA216

Tool/software:

If we use this CURRENT SHUNT MONITOR -INA216 for the current sensing circuit into Li-ion Battery management application, how could I use it for Charging and Discharging current detection?

the current sensing circuit can be recognized the current polarity value? if we define the charging current is positive value, and discharging current is negative, how could I understand it well? thanks.

5 months ago

0 Clemens Ladisch 5 months ago

Guru 317390 points

The INA216 uses GND as the output reference voltage, so it cannot output a negative value.

You need to use a current-sense amplifier with the "bidirectional" feature.

0 Carolus Andrews 5 months ago in reply to Clemens Ladisch

TI__Mastermind 22650 points

Kevin,

Clemens is correct here. To be able to measure in both directions, ie, both positive and negative current, you will need a bidirectional device. The link Clemens included above will take you directly to our bidirectional offerings. If you can provide some additional information on your design needs, I can assist with a product recommendation here.

0 Kevin Wong 5 months ago in reply to Carolus Andrews

Prodigy 30 points

Hi Clemens and Carolus, I mean that the INA216A chip solution how is it to detect the load working current polarity, not for the amplifier power supply voltage, thanks.

0 Clemens Ladisch 5 months ago in reply to Kevin Wong

Guru 317390 points

The INA216 cannot measure IN− > IN+; it will not work at all when the polarity is negative,

0 Carolus Andrews 5 months ago in reply to Clemens Ladisch

TI__Mastermind 22650 points

Kevin,

Check out this video. Amongst other things, this video will show you what we mean when we say bidirectionality in the amplifier and why it is needed here.

With a bidirectional device, the quiescent (zero current) point will be set at the REF voltage provided to the device, and then the linear response will grow towards supply when measuring one polarity, and decrease towards GND when measuring the opposite polarity.

Amplifiers

Amplifiers forum

INA216: How to recognize the current-sensing circuit's current direction/polarity?