The bq25700A is a synchronous NVDC battery buck-boost charge controller,offering low component count, high efficiency solution for space-constraint, multi-chemistrybattery charging applications.
The NVDC-1 configuration allows the system to be regulated at battery voltage, but notdrop below system minimum voltage. The system keeps operating even when the battery is completelydischarged or removed. When load power exceeds input source rating, the battery goes intosupplement mode and prevents the system from crashing.
The bq25700A charges battery from a wide range of input sources including USBadapter, high voltage USB PD sources and traditional adapters.
During power up, the charger sets converter to buck, boost or buck-boost configurationbased on input source and battery conditions. The charger automatically transits among buck, boostand buck-boost configuration without host control.
In the absence of an input source, the bq25700A supports On-the-Go (OTG) function from 1- to 4-cell battery togenerate 4.48 V to 20.8 V on VBUS. During OTG mode, the charger regulates output voltage and outputcurrent.
The bq25700A monitors adapter current,battery current and system power. The flexibly programmed PROCHOT outputgoes directly to CPU for throttle back when needed.