Hi Team, Just investigating options to max battery life in battery only mode- is it always set by the battery UVLO value versus the DC to DC converter output voltage. If this was the case could the DC to DC converter operate in 100% duty cycle ( as the device with be operating with very low current ie PFM mode. Also can you explain what the min off time spec refers to? as the SYS input I thought was just an input?
Hi Ajayt,
The tOnMin is the minimum time the buck (SYS) will be high while switching. The same for the tOffMin, which is the minimum time the buck (SYS) will be low while switching. The duty cycle (output voltage /input voltage) and switching frequency will vary based on your regulated SYS output voltage. The buck will operate on PFM on light loads in order to maintain efficiency. The SYS is the output of the integrated buck on the BQ25120A, you could connect your system to this rail (see applications diagram below). On battery only mode the batuvlo is when the system will essentially shutdown (loss power).
Best regards,
Arelis G. Guerrero
