The SMB239 is a programmable single-cell lithium-ion/lithium-polymer battery charger for a variety of portable applications. The device provides a simple way to charge low- and medium-capacity Li-Ion or Li-Polymer batteries via a USB port or an AC port. Unlike conventional devices, the SMB239’s very small package and high level of configurability simplify design in a wide range of handheld equipment.

Charge control includes qualification, trickle-charge, pre-charge, constant current/constant voltage, and termination/safety settings that are fully programmable via a serial I2C/SMBus making the device truly a flexible solution. Pre-charge, fast charge and termination current levels can be set via I2C commands. The SMB239 offers the option to automatically recharge the battery upon power cycling, only when battery voltage falls 220/390/550mV below the selectable float voltage. This allows for a reduced number of charge/discharge cycles, thereby extending battery life.

The SMB239 offers a wide variety of features that protect the battery pack as well as the charger and input circuitry: over-current, underand over-voltage, and thermal protection. Ultra-precise, 1% accurate, float voltage control improves battery capacity utilization. Status can be monitored via the serial port for charge state and fault conditions. In addition, one LED driver output can be used to signal charge status. As a protection mechanism, when the junction temperature approaches approximately 110°C, the SMB239 will start to reduce charge current to ensure device and system reliability, while charging the battery cell as fast as possible.

The SMB239 is available in a space-saving, 1.3mm x 2.1mm uCSP™ package with lead-free balls and is rated over the –30°C to +85°C temperature range.