INA226-Q1: Power-on-Reset voltage

Kuramochi Tadahiko

Guru 28715 points

Part Number: INA226-Q1
Other Parts Discussed in Thread: INA226

Hi,

Though Power-on-Reset voltage is specified 2V(typ) on the datasheet, operating supply range is specified 2.7V(min.).

So power-on-reset doesn't work certainly if supply voltage is over 2.7V.

Is it correct?

Best Regards,

Kuramochi

over 5 years ago

0 Patrick Simmons over 5 years ago

TI__Mastermind 21805 points

Hello TQ,

Thanks for your interest in our INA226-Q1. That is not a typo or accident in the design. By having the Power-on-reset a little lower than the minimum supply value, that reduces the possibility that the device operated at 2.7V will reset if there is a small transient or ripple on the supply. Also by having the power-on-reset a little lower than the supply requirement, that gives the internal circuitry some time to reset registers before the device starts doing conversions.

0 Kuramochi Tadahiko over 5 years ago in reply to Patrick Simmons

Guru 28715 points

Patrick-san,

Thank you for your answer.

I have an additional question.

Could you show me the deviation of VPOR(Power-on reset threshold ) for our reference?

Best Regards,

Kuramochi

0 Kuramochi Tadahiko over 5 years ago in reply to Kuramochi Tadahiko

Guru 28715 points

Hi,
How is this situation?
Best Regards,
Kuramochi

0 Kuramochi Tadahiko over 5 years ago in reply to Kuramochi Tadahiko

Guru 28715 points

How is this situation?

0 kai klaas69 over 5 years ago in reply to Kuramochi Tadahiko

Guru 140200 points

Hi Kuramochi,

usually the functionality of such a built-in power-on-reset is rather limited. In high reliability designs it's wise to have a brown-out-detection (BOD) elsewhere on the board and to reset the INA226 actively with the microcontroller by writing "4127" (hex) into the configuration register, directly after the microcontroller has experienced a power-on-reset or brown-out-reset.

Kai

0 Kuramochi Tadahiko over 5 years ago in reply to kai klaas69

Guru 28715 points

Kai-san,

Thank you for your help.
However it's not answer for me.
Could you show me the deviation of VPOR(Power-on reset threshold ) for our reference?

Best Regards,
Kuramochi

0 Patrick Simmons over 5 years ago in reply to Kuramochi Tadahiko

TI__Mastermind 21805 points

Hello Kuramochi,

Sorry for the late reply. We unfortunately cannot provide that information. However, I can say that it will definitely be below the operating supply range starting at 2.7V.

0 Kuramochi Tadahiko over 5 years ago in reply to Patrick Simmons

Guru 28715 points

Patrick-san,

Thank you for your help.

Is it guaranteed that VPOR is below 2.7V ?

Best Regards,
Kuramochi

0 Patrick Simmons over 5 years ago in reply to Kuramochi Tadahiko

TI__Mastermind 21805 points

Hello TQ,

I can guarantee that is below the minimum operating supply voltage specified for the part. If you find otherwise, we would definitely like to know and be able to investigate it.

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INA226-Q1: Power-on-Reset voltage