Milpitas, Calif. - Linear Technology's LTC4059A is a fully integrated linear battery charger in a 2-by-2 mm DFN package that can charge a single-cell Li-Ion battery at 900 mA without danger of overheating itself or surrounding components. A patented thermal regulation scheme prevents the junction temperature of the IC from exceeding 115°C by reducing charge current during high-power or high-ambient-temperature operation. The charger, suited to digital still cameras, cell phones, PDAs and USB-equipped handheld devices, requires only two discrete components (input capacitor and a charge-current resistor for programming), with the total solution fitting into a 2.5 by 2.7 mm footprint.
The LTC4059A features an open-drain status pin to indicate the presence of an input supply such as a wall adapter. Other features include a charge-current monitor output for charge termination, a 4.2 volt float voltage that's accurate to 0.6 percent, and 5 percent charge accuracy. The LTC4059A requires no external MOSFET, sense resistor or blocking diode. The device works from a 3.75 to 8-volt input. During shutdown, the supply current is only 10 microamps and battery drain current is less than 1 microamp.
The LTC4059A is rated for operation from -40 to 85°C. Pricing starts at $1.45 each in 1,000-piece quantities.