BQ25121: PMID maximum output capacitor value

Hello,
The capacitor on PMID can be increased up to 22uF. Can you please post your schematic to debug this issue.
Regards,
Raheem

Jeffery,

it is likely that the BAT pin was holding some voltage when this was happening. It is likely that you dont have a battery connected. to test the theory, can you discharge the BAT pin (if there is no battery) to GND and plug VIN?

thanks,
Gautham

Hi Gautham,

Yes, you're right.
It is occurred when Vin is plugged in under condition that battery isn't connected and battery voltage is 0V.
Could you explain and advise about this issue?

Regards
Jeffrey

Jeffrey,

One of the requirements on the older version of silicon is that the battery voltage stay outside the range of 0.2-0.7V (datasheet asks for <1V) when turning ON. Can you use the BQ25120A?

regards,
gautham

Hi Gautham,

No, I use BQ25121YFPR.
You mean that PMID turns on when battery voltage stay outside the range of 0.2-0.7V (datasheet asks for <1V).
But if output capacitor of PMID is changed from more than 15uF to 4.7uF~10uF, PMID voltage is normal (5V) under condition that battery isn't connected and battery voltage is 0V.
So I want to know the maximum output capacitor value of PMID.
Please let me know it.

Regards
Jeffrey

Hi Raheem,

I already read that PMID can be increased up to 22uF in datasheet.

But if output capacitor of PMID is changed from more than 15uF to 4.7uF~10uF, PMID voltage is normal (5V) under condition that battery isn't connected and battery voltage is 0V.

Please refer to the attached schematic.

Regards

Jeffrey

Hi Gautham,

Could you reply on my questions?

Regards
Jeffrey

Hi Racheem,

Could you reply on my questions?

Regards
Jeffrey

Hello Jeffrey,
Is the BAT pin tied to ground?

Regards,
Raheem

Hi Raheem,

No, BAT pin isn't tied to ground.
BAT pin is floated when battery isn't connected.

Regards
Jeffrey

Jeffrey,
As stated above, this issue occurs only when VBAT is between 0.2 and 0.7V. PMID should operate normally if you're outside this range. Please let me know if i misunderstood your question / concern.
Regards,
Raheem