BQ78350 reference manual (sluubd3e, page 15) describes OTFET signal as "FET action in overtemperature mode"; this signal is also used inchapters 3.7.1 / 3.7.2 Overtemperature in Charge / discharge protection.
However this signal is also used for undertemperature which is not mentioned in the documentation; only when this bit is set, undertemperature condition switches off FET's.
Hi Matt,
the issue is easy to reproduce (see screenshots)
- start condition is OTFET (in FETOPTIONS) is set (screenshot 1), protection settings are normal (markings in screenshot 2: UTC threshold -25degC, Recovery -20degC), temperature measurement shows room temperature (~22degC, screenshot 3); no fault indication, everything is normal
- changed UTC protection to 25degC / 27degC (screenshot 4) so UTC should be activated at current temperature;
when trying to charge, charge current is shortly activated, then XCHG is getting active and no charging is possible (Mosfets for charge are off), see screenshot 5
- deactivated OTFET in FETOPTIONS (screenshot 6)
- charging is now possible, even if UTC is still active (screenshot 7)
