LTC4085-1

Seamless Transition Between Input Power Sources: Li-Ion Battery, USB and 5V Wall Adapter
215m Internal Ideal Diode Plus Optional External Ideal Diode Controller Provide Low Loss PowerPathTM When Wall Adapter/USB Input Not Present
Load Dependent Charging Guarantees Accurate USB Input Current Compliance
4.1V Float Voltage Improves Battery Life Span and High Temperature Safety Margin
Constant-Current/Constant-Voltage Operation with Thermal Feedback to Maximize Charging Rate Without Risk of Overheating*
Selectable 100% or 20% Input Current Limit (e.g., 500mA/100mA)
Battery Charge Current Independently Programmable Up to 1.2A
Preset 4.1V Charge Voltage with 0.8% Accuracy
C/10 Charge Current Detection Output
Tiny (4mm * 3mm * 0.75mm) 14-Lead DFN Package

The LTC^®4085-1 is a USB power manager and Li-Ion battery charger designed for portable battery-powered applications. The part controls the total current used by the USB peripheral for operation and battery charging. The total input current can be limited to 20% or 100% of a programmed value up to 1.5A (typically 100mA or 500mA). Battery charge current is automatically reduced such that the sum of the load current and charge current  does not exceed the programmed input current limit.

The LTC4085-1 includes a complete constant-current/ constant-voltage linear charger for single cell Li-Ion batteries. This 4.1V version of the standard LTC4085 is intended for applications which will be operated or stored above approximately 60. Under these conditions, a reduced fl oat voltage will trade-off initial cell capacity for the benefi t of increased capacity retention over the life of the battery. A reduced fl oat voltage also minimizes swelling in prismatic and polymer cells, and avoids open CID (pressure fuse) in cylindrical cells.

The LTC4085-1 also includes a programmable termination timer, automatic recharging, an end-of-charge status output and an NTC thermistor.

The LTC4085-1 is available in a 14-lead low profi le 4mm * 3mm DFN package.