The LM3658 is a single chip charger IC designed for hand-held applications. The LM3658 can safely charge and maintain a single cell Li-Ion/Polymer battery operating from an AC wall adapter or the USB power source. Input power source selection of USB/AC is automatic. With both power sources present, the AC power source has priority. Charge current is programmed through an external resistor when operating from an AC wall adapter allowing charge currents from 50mA to 1000mA. When the battery is charged using USB power, charge currents of 100mA or 500mA are pin selectable. The termination voltage is controlled to within plus or minus .35% of 4.2V. The LM3658 requires few external components and integrates internal Power FETs, reverse current protection and current sensing. The internal power FETs are thermally regulated to obtain the most efficient charging rate for a given ambient temperature.
The LM3658 operatesin five phases: pre-qualification mode, constant-current mode, constant-voltage mode, topoff mode and maintenance mode. Additionally the LM3658-B charger IC operates as a linear Regulator or in "LDO mode" when the AC wall adapter is connected and no battery is present. Optimal battery management is obtained through the integration of thermal protection, battery temperature measurement and a multi-mode safety timer. The LM3658 provides two open-drain outputs for LED status indication or connection to a GPIO.
The LM3658 evaluation kit supports complete functional evaluation of the battery charger IC. All user accessible functions of the circuit can be controlled through jumpers. The evaluation kits are available in three options: LM3658SDEV, LM3658SDAEV, and LM3658SDBEV. For details of the various options, please refer to the ordering information table located in either the data sheet or Application Note 1517.