Recommended tool:
bq24040 is the recommended alternative to the LM3658 devices. Please refer to the bq24040EVM for new device evaluation.
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.
Features
- Integrated power FETs with thermal regulation
- Charges from either an AC wall adapter or USB power source with automatic source selection
- 50mA to 1000 mA charge currents using AC wall adapter
- Pin-selectable USB charge currents of 100 mA or 500 mA
- LDO mode with 1A of source current is automatically invoked when the battery is absent and the AC wall
adapter is connected - Continuous battery temperature monitoring
- Built-in multiple safety timers
- Charge status indication
- Continuous over-current and temperature protection
- Near-depleted battery pre-conditioning
- Sleep mode with ultra low quiescent current
- On-board Kelvin-sensing achieves plus or minus .35% termination accuracy.
- Maintenance mode with automatic recharge
- Thermally enhanced 3 mm x 3 mm LLP package
Applications
- Smartphones
- Digital still cameras
- PDAs
- Hard drive and flash-based MP3 players
- USB-powered devices