Single-cell linear charger in a 6-bump DSBGA
The Texas Instruments BQ25101HYFPT is a single-cell linear charger for Lithium Ion/Polymer batteries, delivering a programmable constant charge current up to 250 mA. It targets space-constrained portable designs where the 6-XFBGA/DSBGA package (1.5 mm × 1.5 mm typical) keeps the PCB footprint minimal. The charger operates from a supply up to 6.45 V and terminates at a battery regulation voltage of 4.35 V.
250 mA charge current — sizing the charge time
The 250 mA maximum charge current sets the charge rate for a single-cell Li-Ion pack. For a 500 mAh cell, a full constant-current charge takes roughly two hours at this rate, assuming the power supply can deliver the input current without dropout. The current is programmable via an external resistor, so the BOM can tune the charge profile to the battery capacity.
Fault protection and temperature range
Built-in fault protection covers over-temperature, over-voltage, and short-circuit conditions — three safeguards that matter when the battery is in a sealed enclosure or subject to a fault on the input rail.
Package and mounting
The 6-DSBGA package is a 0.5 mm pitch wafer-level chip-scale package. Surface-mount assembly requires a solder stencil designed for the bump pattern and a reflow profile compatible with the package's moisture sensitivity level. The small body means the thermal pad area is limited — the PCB copper plane under the package acts as the primary heat sink during charging.