28-QSOP Li-Ion charger for 1-4 series cells
The MAX1737EEI+T is a Li-Ion battery charger IC from Analog Devices that handles 1 to 4 series cells, charging up to a 16.8 V pack voltage. It operates over -40°C to 85°C, suiting it for industrial and portable equipment that sees temperature extremes.
Constant-current charging with timer-based termination
Charging is constant-current only — the IC regulates charge current without a voltage-regulation loop, relying on an external timer to terminate the charge cycle. The programmable timer feature lets the designer set the charge duration via an external capacitor, matching the cell capacity and charge rate. The maximum supply voltage is 28 V, giving headroom for a 16.8 V pack from a 19 V or 24 V wall adapter without an external pre-regulator. The IC integrates the charge-control FET and current-sense circuitry, reducing external component count to the timer cap, input cap, and a few resistors.