REF3025: output is 2.64V when connected to INA828 REF pin

Tess Chen

Part Number: REF3025

Hi,

When using REF3025 as the voltage reference for INA828, the output of REF3025 is changed to 2.64V. And REF3025 could work when it's not connected to INA828. Could you please give some suggestions on solving this issue? Thanks.

over 5 years ago

0 Marcoo Z over 5 years ago

TI__Mastermind 19580 points

Hi Tess,

Can you provide us a schematic?

0 Tess Chen over 5 years ago in reply to Marcoo Z

TI__Intellectual 2675 points

Hi Marcoo,

Please find schematic in the below. And there is a 1uF cap between 2.5V to ground.

0 Marcoo Z over 5 years ago in reply to Tess Chen

TI__Mastermind 19580 points

Hi Tess,

The REF3025 is a 5.5V Vin abs max device. I see 8.6V and this is causing issues on the device. I suspect if this is changed to The RoC it can be fixed. Keep in mind that this particular device already faced 8.6V which violates ABS MAX.

0 Tess Chen over 5 years ago in reply to Marcoo Z

TI__Intellectual 2675 points

Hi Marcoo,

Sorry for the confusion. The actual input for REF3025 is 5V and schematic is shown in the below. Issue phenomena is repetitive when change to the same another part. And REF3025 could work as normal when not connected to the INA828.

Best Regards,

Tess Chen

0 Marcoo Z over 5 years ago in reply to Tess Chen

TI__Mastermind 19580 points

Hi Tess,

I suspect that the INA828 needs the VREF pin to sink/source current. The REF30 can only source and not sink. And so when the REF30 has to sink, the voltage goes out of regulation.

Can you measure the current of the REF30 output pin?

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REF3025: output is 2.64V when connected to INA828 REF pin