INA1H94-SP: Avoid back-feeding/back-powering when VCC is off

Mina Shawky

Part Number: INA1H94-SP

Hello,

I'm using the op amp in a the same application as shown in figure 7-2 in the datasheet. One of the requirements of the battery is a disabled state where all on the on-board electronics are off to lower current draw and lengthens the storage duration. This results in back-feeding on the VCC and REF pins. What's TI's recommendation on avoiding this with a live input with VCC/REF off?

Best,

Mina

6 days ago

0 Robert Clifton56 6 days ago

TI__Mastermind 28250 points

Hi Mina,

The only solution I can think of is using some kind of switch, like a MUX, that disconnects the inputs of the INA1H94-SP to the battery. It's not an elegant solution but it will prevent the back-feeding of the REF and VCC.

Best Regards,

Robert Clifton

0 Mina Shawky 6 days ago in reply to Robert Clifton56

Prodigy 40 points

Hey Robert,

Do you have any recommendation on switches that would've minimal affect on the measurement? I was thinking some sort of an analog switch but open to suggestions.

Best,

Mina

0 Robert Clifton56 5 days ago in reply to Mina Shawky

TI__Mastermind 28250 points

Hi Mina,

You will want something that has minimal on resistance, magnitudes smaller than the 380kohms. What kind of analog switches were you investigating?

Best Regards,

Robert Clifton

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INA1H94-SP: Avoid back-feeding/back-powering when VCC is off