JAJSMK1 August 2023 BQ25756
PRODUCTION DATA
In forward boost mode or reverse buck mode, the output capacitor conducts high ripple current. The output capacitor RMS ripple current is given by where the minimum VAC corresponds to the maximum capacitor current.
A 5-mΩ output capacitor ESR causes an output voltage ripple of 74 mV as given by:
A 140-μF output capacitor causes a capacitive ripple voltage of 66 mV as given by:
A combination of ceramic and bulk capacitors should be used to provide low ESR and high ripple current capacity. Ceramic capacitors should be placed close to the switching half-bridge. Given total bulk output capacitance, it is recommended to distribute equally on either side of RBAT_SNS. The complete schematic is a good starting point for CBAT for typical applications.