Other Parts Discussed in Thread: TPS23758
Almost everything is perfect. Except... when there is no battery.
SYS is maintained at 3.7-3.9V as specified by registers
Except for an occasional glitch which wipes out my system :( (Brownout detector trips at 2.5v)
The SYS rail looks like this:
These are my register settings
BQ24295 REG00 = 5E
BQ24295 REG01 = 1F
BQ24295 REG02 = 60
BQ24295 REG03 = 11
BQ24295 REG04 = B2
BQ24295 REG05 = BE
BQ24295 REG06 = 9F
BQ24295 REG07 = 4B
BQ24295 REG08 = 05
BQ24295 REG09 = 01
Power comes from a 5V, 3A external POE Input (TPS23758) which I've measured to not glitch even a hair (as far as I can tell) (I've run load tests on this external DC Rail and know it's okay up to 3A)
I think it has to do with drawing over a certain amount of current (not exactly sure how much but lets say about 500ma-700ma)
When I draw less, there's no glitch on SYS.
This drop/glitch happens more often on some of my boards than others.
Is there a certain current limit the causes BQ24295 to drop SYS when no battery is present even though there is plenty of external voltage/current?
Thanks so much for any ideas!
Jeff