The BQ24074RGTRG4 is a single-cell linear Li-ion charger from Texas Instruments, built for USB-powered portable designs. The headline rating is a 1.5 A maximum charge current — that sets the charge-time floor for a 4.2 V battery pack. At 1.5 A, a 2000 mAh cell charges in roughly 80 minutes from flat, assuming the input supply can deliver the current without drooping below the dropout threshold.
The supply input accepts up to 10.2 V maximum, so it tolerates a 5 V USB bus or a 9 V wall adapter without an external pre-regulator. The charger integrates over-temperature, over-voltage, reverse-current, and short-circuit fault protection — that list covers the common failure modes in a portable product and eliminates the need for discrete protection components on the power path. Charge current and charge timer are programmable via external resistors, giving the BOM engineer control over the charge profile without firmware involvement. The single-cell 4.2 V termination voltage is fixed — no resistor divider needed for the target chemistry.
Temperature grade and package — layout and environment
The 0.50 mm pitch VQFN demands a well-tuned solder stencil aperture; a four-layer board with thermal vias under the pad is the standard layout for sustained high-current charging.