DESCRIPTION
The LTC®4090/LTC4090-5 are USB power managers plus high voltage Li-Ion/Polymer battery chargers. The devices control the total current used by the USB peripheral for operation and battery charging. Battery charge current is automatically reduced such that the sum of the load current and the charge current does not exceed the programmed input current limit. The LTC4090/LTC4090-5 also accommodate high voltage power supplies, such as 12V AC/DC wall adapters, FireWire, or automotive power.

FEATURES
■ Seamless Transition Between Power Sources: LiIon Battery, USB, and 6V to 36V Supply (60V Max)
■ 2A Output High Voltage Buck Regulator with BatTrackTM Adaptive Output Control (LTC4090)
■ Internal 215mΩ Ideal Diode Plus Optional External
   Ideal Diode Controller Provides Low Loss Power
   Path When External Supply / USB Not Present
■ Load Dependent Charging from USB Input Guarantees Current Compliance
■ Full Featured Li-Ion Battery Charger
■ 1.5A Maximum Charge Current with Thermal Limiting
■ NTC Thermistor Input for Temperature Qualifi ed
   Charging
■ Tiny (3mm × 6mm × 0.75mm) 22-Pin DFN Package

APPLICATIONS
■ HDD-Based Media Players
■ Personal Navigation Devices
■ Other USB-Based Handheld Products
■ Automotive Accessories