Maxim Integrated Products’ MAX8671X is a highly integrated power-management IC (PMIC) that provides a single-cell, Li-ion/Li-polymer charger that seamlessly distributes power within portable systems. The device's smart power selector circuitry efficiently distributes power among a USB source and an ac-adapter source, battery, and system load. When external power is connected, the circuitry allows the system to operate with no battery or a deeply discharged battery. It automatically switches the system load from the battery and makes the best use of limited USB or adapter power while charging the battery from input power not used by the system.
The device also integrates three 2-MHz, stepdown dc-dc converters, and two low-quiescent-current linear regulators to provide five regulated output voltages. All necessary power switches and current-sense circuitry are included on the chip. The device also includes thermal-limiting circuitry that reduces the battery-charge rate to prevent the charger from overheating. The MAX8671X is available in a thermally enhanced 5-mm x 5-mm, 40-pin TQFN package. Prices start at $2.95 for 1000 pieces.