JAJSKU9B December 2022 – February 2024 BQ25628 , BQ25629
PRODUCTION DATA
After the input current and voltage limits are set, the converter is enabled and the HSFET and LSFET start switching. If battery charging is disabled, the BATFET turns off. Otherwise, the BATFET stays on to charge the battery. Converter startup requires the following conditions:
The BQ25628 and BQ25629 provide soft start when the system rail is ramped up by setting IINDPM to its lowest programmable value and stepping up through each available setting until reaching the value set by IINDPM register. Concurrently, the system short protection limits the output current to approximately 0.5 A when the system rail is below VSYS_SHORT.
The device uses a highly efficient 1.5-MHz, fixed frequency pulse width modulated (PWM) step-down switching regulator. The internally compensated feedback loop keep tight control of the switching frequency under all conditions of input voltage, battery voltage, charge current and temperature, simplifying output filter design.
The device switches to pulse frequency modulation (PFM) control at light load condition. The PFM_FWD_DIS and PFM_OTG_DIS bit can be used to disable the PFM operation in buck and boost respectively.