USB battery charger sports buck boost, buck converters

Milpitas, Calif.—Linear Technology Corp. announces the LTC3558, an efficient, multi-function power management solution for handheld applications.

The LTC3558 integrates a stand-alone Li-Ion/Polymer battery charger and two high efficiency synchronous regulators—one buck-boost and one buck—and is offered in a compact low-profile 3mm x 3mm QFN package.

The linear battery charger can deliver up to 950mA charge current from a wall adapter supply, or up to 500mA charge current from a USB port. The LTC3558's stand-alone autonomous operation simplifies design, eliminating the need for an external microprocessor for charge termination. Both switching regulators are designed to operate over the Li-Ion/Polymer range of 2.7V to 4.2V while delivering output currents up to 400mA each.

The LTC3558's integrated synchronous buck regulator features 100% duty cycle operation, while the buck-boost regulator is capable of regulating its programmed output voltage (typically 3.3V) over the entire Li-Ion/Polymer operating range. The integrated low RDS(ON) switches enable efficiencies as high as 92%, maximizing battery run time. In addition, Burst Mode operation optimizes efficiency at light loads with a quiescent current of only 20µA for the buck-boost and 35uA for the buck (<1µA in shutdown for each). The high 2.25MHz switching frequency allows the utilization of tiny low cost capacitors and inductors less than 1mm in height. Furthermore, the regulators are stable with ceramic output capacitors, achieving very low output voltage ripple.

Pricing: Starts at $2.35 each for 1,000-piece quantities.
Availability: From stock.

Datasheet: Click here.

Linear Technology,

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