BQ25638: status of the I2C bus and other signals when not powered

Ignacio Majcherczyk

Part Number: BQ25638

Tool/software:

Dear forum

My question is what is the status of the I2C bus when the BQ25638 is powered off, with no Vbat nor Vbus voltages present

but with the I2C bus attached to an active I2C bus and other powered I2C peripherals

Also I need to know if the /PG, STAT, /CE, /INT signals will draw current or cause contention with active lines when BQ25638 is so powered down.

best regards

Ignacio

over 1 year ago

0 Ning T over 1 year ago

TI__Guru 59511 points

Hi Ignacio,

The device will not support I2C when it is completely off.

VBAT or VSYS is usually used as the pull-up for /PG, STAT, /CE, /INT signals. So when no VBAT and no VBUS, there should not be no current.

Thanks,

Ning.

0 Ignacio Majcherczyk over 1 year ago in reply to Ning T

Prodigy 170 points

Hello Ning

my question is if the BQ25638 will create contention with an active I2C bus pulling the lines low or to an invalid level.

The same question applies to the /PG, STAT, /CE, /INT signals. Will it be pulled low or to an invalid level if (i.e) they are pulled up to an 1.8V level with resistors?

cheers

Ignacio

+1 Ning T over 1 year ago in reply to Ignacio Majcherczyk

TI__Guru 59511 points

Hi Ignacio,

It should not when the device is off.

Thanks,

Ning.

Power management

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BQ25638: status of the I2C bus and other signals when not powered