Charger IC for 1-3 cell Li-Ion packs
The BQ24133RGYR: It handles a maximum charge current of 2.5 A and accepts a supply voltage up to 17 V, making it suitable for multi-cell portable equipment and field-replaceable battery packs.
Charge current programmability and fault protection
The charge current is constant and programmable via an external resistor — the BQ24133RGYR does not include a digital interface, so the charge profile is set by the passives around the IC. Battery regulation voltage is fixed at 4.2 V per cell. On-chip fault protection covers overcurrent, overtemperature, and overvoltage conditions, which means the IC can shut itself down before the passives or the battery take damage.
Industrial temperature range and package
The 24-VFQFN Exposed Pad package with a 5.5x3.5 mm footprint needs a thermal via array under the paddle to pull heat from the switching FETs; the layout guide in the datasheet calls for a solid copper pour on the bottom layer.