The LTC4075HVX is a standalone linear charger that is capable of charging a single-cell Li-Ion/Polymer battery from both wall adapter and USB inputs. The charger can detect power at the inputs and automatically select the appropriate power source for charging.

No external sense resistor or blocking diode is required for charging due to the internal MOSFET architecture. The LTC4075HVX features a maximum 22V rating for both wall adapter and USB inputs although charging stops if the selected power source exceeds the overvoltage limit. Internal thermal feedback regulates the battery charge current to maintain a constant die temperature during high power operation or high ambient temperature conditions. The float voltage is fixed at 4.2V and the charge current is programmed with an external resistor. The LTC4075HVX terminates the charge cycle when the charge current drops below the programmed termination threshold after the final float voltage is reached.

Other features include automatic recharge, undervoltage lockout, charge status outputs, and “power present” status outputs to indicate the presence of wall adapter or USB power. No trickle charge allows full current from the charger when a load is connected directly to the battery.

Applications

• Cellular Telephones
• Handheld Computers
• Portable MP3 Players
• Digital Cameras