INA237: Device ground and load ground - isolation

Varban Metodiev

Part Number: INA237

Hi,

I am a bit confused about the INA237AIDGSR IC ground and load ground relationship...

The datasheet mentions "the common-mode input range and device supply voltage are independent of each other" and the following diagram denotes the two grounds with different symbols:

It is then stated that "The differential shunt voltage is measured between the IN+ and IN– pins, while the bus voltage is measured with respect to device ground."

May someone please explain me:

1) Can I expect any kind of isolation between the IC ground and the load ground in case I use only the IN+/IN- pins with a shunt, without connecting VBUS anywhere?

2) Can the VBUS be referenced to the load ground only and stay isolated from the IC power supply ground?

Thanks!

7 months ago

+1 Mitch M 7 months ago

TI__Mastermind 19385 points

Hello Varban,

Thank you for using the TI forum. I agree that this figure is a little confusing. The GND of the load and the INA should actually be the same GND. If the levels are not compatible, then you can use an isolator device, as shown in these reference designs:

https://www.ti.com/tool/TIDA-00313

https://www.ti.com/tool/TIDA-01608

Regards,

Mitch

0 Varban Metodiev 7 months ago in reply to Mitch M

Intellectual 570 points

Hello Mitch,

Thank you for the clarifications!

Regards,

Varban

0 Mitch M 6 months ago in reply to Varban Metodiev

TI__Mastermind 19385 points

You're welcome!

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INA237: Device ground and load ground - isolation