Single-cell Li-Ion charger that doesn't need a heatsink
The BQ24210DQCT is a linear charger IC for single-cell Lithium Ion battery packs, delivering a programmable constant charge current up to 800 mA with a fixed 4.2 V termination voltage. The 10-WSON package (3x2 mm) with exposed pad keeps junction temperature under control even at the full 800 mA charge rate, so you skip the external heatsink and keep the board layout tight. Input supply maxes at 18 V, which covers 5 V USB, 9 V wall adapters, and 12 V rails without a front-end regulator.
Programmable charge current — set it with one resistor
The charge current is constant and programmable via a single external resistor. At the 800 mA maximum, the thermal dissipation in the WSON pad is manageable with proper PCB copper area — a 2-layer board with a 1-inch-square ground plane under the pad keeps the die below the thermal regulation threshold during a full charge cycle.
On-chip fault protection covers the common failure modes
Over-temperature, over-voltage, and short-circuit protection are integrated, so a single-chip charge controller handles the safety interlocks without external comparators or supervisory ICs. The thermal regulation loop reduces charge current if the die temperature climbs above the internal limit, which matters when the ambient hits 85°C and the charger is running at full rate.