USB Compatible Switching Power Managers/Li-Ion Chargers with Overvoltage Protection

The LTC4098/LTC4098-1 are high efficiency USB Power-Path controllers and full-featured Li-Ion/Polymer battery chargers. They seamlessly manage power distribution from multiple sources including USB, wall adapter, automotive, Firewire or other high voltage DC/DC converters, and a Li-Ion/Polymer battery.

The LTC4098/LTC4098-1’s internal switching regulator automatically limits its input current for USB compatibility. For automotive and other high voltage applications, the LTC4098/LTC4098-1 interface with an external switching regulator to provide a high efficiency high voltage power path. Both the USB and the optional high voltage inputs feature Bat-Track optimized charging to provide maximum power to the application and ease thermal issues in high power density applications with input supplies from 5V to as high as 38V.

An overvoltage circuit protects the LTC4098/LTC4098-1 from high voltage damage on the USB/wall adaptor inputs with an N-channel FET and a resistor.

The LTC4098/LTC4098-1 are available in a 20-lead, 3mm × 4mm × 0.75mm QFN surface mount package.

Float Voltage

LTC4098

4.2V (1-cell Li-Ion/Li-Polymer)

LTC4098-1

4.1V (1-cell Li-Ion/Li-Polymer)

LTC4098-3.6

3.6V (1-cell LiFePO4)

Applications

* Media Players

* GPS

* PDAs

* Smart Phones

* Switching Regulator with Bat-Track™ Adaptive Output Control Makes Optimal Use of Limited Power Available from USB Port to Charge Battery and Power Application

* Overvoltage Protection Guards Against Damage

* Bat-Track External Step-Down Switching Regulator Control Maximizes Efficiency from Automotive, Firewire and Other High Voltage Input Sources

* 180mΩ Internal Ideal Diode Plus External Ideal Diode Controller Seamlessly Provide Low Loss PowerPath™ when Input Power is Limited or Unavailable