Linear Technology introduces the LTC4075HVX, a standalone dual-input linear battery charger that manages charging single-cell Li-Ion/Polymer batteries from two separate power sources: a wall adapter and USB. Using a constant-current/constant-voltage algorithm, the charger can deliver up to 950mA of charge current from a wall adapter supply, or up to 850mA of charge current from a USB supply and automatically sense the presence of voltage at each input. The final float voltage accuracy is ±0.6% in either case.
The LTC4075HVX provides protection up to 22V(max) on both inputs. If the selected power source exceeds the overvoltage lockout limit, the LTC4075HVX will stop charging. The LTC4075HVX disables the trickle charge function, benefiting systems requiring higher charge current during low battery conditions. Applications include PDAs, MP3 players, lightweight portable medical and test equipment and large color screen cell phones. The LTC4075HVX is equipped with a patented thermal regulation scheme that maximizes the charging rate without the risk of overheating. The device is flexible, enabling programmability via a single resistor of wall adapter supply charge current, USB supply charge current and charge termination current. As a standalone charger, the LTC4075HVX simplifies design, since no external microprocessor is required for charge termination.
The IC features undervoltage lockout, automatic recharge, charge status and "power present" status indication. The LTC4075HVX draws <12uA of current from the battery terminal in both standby and shutdown modes, preserving battery energy. It is offered in a low profile (0.75mm) 10-lead 3mm x 3mm DFN package. The total solution footprint is less than 25mm2 since no external MOSFET, sense resistor or blocking diode is required. The LTC4075HVX is rated for operation from -40°C to 85°C. 1,000-piece pricing begins at $2.00 each.
