Proper battery management with PCF85263A

[brenconsult]

Two questions:

1. Will the chip still function properly if the backup battery is dead or removed?

2. What is the exact external circuit we would need to use with a lithium primary coin cell and this chip? The user manual (UM10301) and the datasheet are not clear. Another thread on this forum says that the chip has the needed blocking diode in it, but that an external resistor of unspecified value is still needed.  We want to do what's proper regarding UL.

Thanks,

Scott

[brenconsult]

Thank you!

[diazmarin09 · Accepted solution]

Hello Scott,

I hope all is great with you.

Please review the information below:

1. As long as the VDD power is above the threshold voltage, it will function properly. Please find further information at chapter 7.11 from datasheet. The battery switch circuit may be disabled when not used.

2. In this case, I recommend to use the OM13510 as a reference for your design. You may find further information in the user manual.

I hope this information helps.

Regards,

David