The LTC4000 features an intelligent PowerPathTM topology that preferentially provides power to the system load when input power is limited. The LTC4000 controls external PFETs to provide low loss reverse current protection, efficient charging and discharging of the battery and instant-on operation to ensure that system power is available at plug-in even with a dead or deeply discharged battery. External sense resistors and precision sensing enable accurate currents at high efficiency, allowing the LTC4000 to work with converters that span the power range from milliwatts to kilowatts.
The LTC4000's full-featured controller charges a variety of battery chemistries including lithium-ion/polymer/phosphate, sealed lead acid (SLA), and nickel-based. The device also provides charge status indicators through its FLT and CHRG pins. Other features of the battery charger include: ±0.2% programmable float voltage, selectable timer or C/X current termination, temperature-qualified charging using an NTC thermistor, automatic recharge, C/10 trickle charge for deeply discharged cells and bad battery detection.
The LTC4000 is housed in a low profile (0.75mm) 28-pin 4mm x 5mm QFN package and a 28-lead SSOP package. The device is guaranteed for operation from -40°C to 125°C. 1,000-piece pricing starts at $3.95 each.