Charger IC for single-cell Li-Ion with USB input
The MAX8903GETI+ is a single-cell lithium-ion battery charger IC from Analog Devices' Smart Power Selector™ series, designed for applications that draw power from a USB port or a DC wall adapter. It integrates a constant-current, constant-voltage charging algorithm with programmable charge current up to 2 A and a 4.2 V battery regulation voltage. The part accepts a supply voltage up to 16 V, covering the range of standard USB (5 V) and common 9–12 V wall adapters without an external pre-regulator. Over-voltage fault protection on the input is built in, so a transient above the 16 V absolute maximum won't cascade into the battery.
Package, temperature grade, and board-fit
The industrial temperature range is the full operating envelope; no derating is required across the band for the 2 A charge current as long as the PCB thermal resistance is managed.
Programming and fault handling
Charge current and safety timer are programmable via external resistors, giving the BOM engineer control over the charge profile without firmware. The constant-current phase is set by a resistor from the ISET pin to ground; the timer sets a maximum charge duration as a backup against a failed termination. Over-voltage protection on the input rail is the only listed fault protection — the part does not include reverse-battery or thermal regulation on the datasheet summary, so the system design should account for those at the board level if the application requires them.