BQ27520-G4: I2C fail safe function of BQ27520-G4

Tohru Sakuma

Part Number: BQ27520-G4

Our customer is considering VREGIN will connect to the battery (3.2V to 4.2V) directly..

(this configuration is general, as shown in the reference circuits such as data sheets)

Their concern in this case is that the fuel gauge IC cannot start when the battery is completely discharged.

On the other hand, MCU is active supplied from the AC adapter.

At this time, they would like to check whether the breakdown voltage (tolerant) of I2C port of BQ27520-G4 to MCU become a problem.(broken??) or not.

If BQ27520-G4 has fail safe feature etc for such a case , it should be '' no problem "

Though this configuration seems to be widely adopted by other companies, could you give us your comment about it ?

Best regards

T.Sakuma

0 Tohru Sakuma over 3 years ago

Could you give us your comments about this ? since we are waiting for 3 days.

Best regards

T. Sakuma

0 Matt Sunna over 3 years ago in reply to Tohru Sakuma

Hi Sakuma-san,

The datasheet states that the abs max voltage for these pins is 5.5V, so it should not damage the device.

Best regards,

Matt

0 Tohru Sakuma over 3 years ago in reply to Matt Sunna

Matt san

At the case of BQ27520(no power due to battery discharge ) and MCU(power on supplied from external power)

Is there no damage of I2C port of BQ27520 connecting to I2C port of MCU ?

Does I2C port of BQ27520 have fail safe function to support such a case ?

T. Sakuma

0 Matt Sunna over 3 years ago in reply to Tohru Sakuma

Hi Sakuma-san,

Are you asking if the BQ27520 has protection against damaging the MCU?

Thanks,

Matt

0 Tohru Sakuma over 3 years ago in reply to Matt Sunna

Matt san

Will I2C port of BQ27520 NOT be damaged at the case of BQ27520(no power due to battery discharge ) and MCU(power on supplied from external power) ?

If so, could you tell us the reason not to do it ?

Best regards

T .Sakuma

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