16.2 A buck-boost charger with I²C programmability
The BQ25730RSNR is a buck-boost battery charger from Texas Instruments that handles 1 to 5 series cells with a programmable charge current up to 16.2 A. The I²C interface lets you set the charge current and voltage in firmware, so you can tune the charging profile for different battery chemistries without swapping resistors. Input voltage tolerance goes up to 26 V, which covers common power bricks from 5 V to 24 V, including USB-C PD adapters. The buck-boost topology means it can charge a multi-cell pack even when the input voltage is lower than the battery voltage — useful for 2S or 3S packs from a 5 V USB source.
Fault protection and thermal footprint
On-chip over-current, over-temperature, and over-voltage protection reduce the need for external supervisory circuits.