1.5 A Li-Ion charger with integrated power FETs
The Texas Instruments BQ24032ARHLTG4 is a linear Li-Ion/Polymer charger IC from the bqTINY III series, designed for single-cell battery packs with a 4.2 V termination voltage. It integrates the pass transistor and current-sense resistor, so no external MOSFET or sense resistor is needed — the BOM stays tight for space-constrained portable designs like handheld instruments, medical monitors, or IoT edge nodes.
Charge current and thermal budget
The charge current is constant-current programmable up to 1.5 A max. A 5 V USB input charging at 1.5 A into a 3.7 V cell dissipates roughly 2 W; the PCB copper area is the heatsink.
Input voltage and fault protection
The supply input handles up to 16 V, so the part can run from a 5 V USB port or a 12 V wall adapter without a front-end regulator. On-chip fault protection covers over-temperature, reverse current (blocking a charged battery from back-driving the input), and short-circuit on the output. The programmable timer and current set point are set with external resistors — no I²C bus needed.