LTC3556 Datasheet | Linear Technology

Features POWER MANAGER n High Efficiency Switching Power Path TM Controller with Bat-Track TM Adaptive Output Control n Programmable USB or Wall Current Limit (100m A/500m A/1A) n Full Featured Li-Ion/Polymer Battery Charger n Instant-On Operation with a Discharged Battery n 1.5A Maximum Charge Current n Internal 180mΩ Ideal Diode Plus External Ideal Diode Controller Powers Load in Battery Mode n Low No-Load IQ when Powered from BAT (<30µA) DC/DCs n Dual High Efficiency Buck DC/DCs (400m A/400m A IOUT) n High Efficiency Buck-Boost DC/DC (1A IOUT) n All Regulators Operate at 2.25MHz n Dynamic Voltage Scaling on Two Buck Outputs n I2C Control of Enables, Mode, Two VOUT Settings n ENALL Pin with Power-Up Sequence Control n Low No-Load Quiescent Current: 20µA Each APPLICATIONS n HDD-Based MP3 Players, PDAs, GPS, PMPs n Other USB-Based Handheld Products High Efficiency USB Power Manager with Dual Buck and Buck-Boost DC/DCs DESCRIPTION The LTC®3556 is a highly integrated power management and battery charger IC for Li-Ion/Polymer battery applications. It includes a high efficiency current limited switching Power Path manager with automatic load prioritization, a battery charger, an ideal diode, and three synchronous switching regulators (two bucks and one buck-boost). Designed specifically for USB applications, the LTC3556’s switching power manager automatically limits input current to a maximum of either 100m A or 500m A for USB applications or 1A for adapter-powered applications. The LTC3556’s switching input stage transmits nearly all of the 2.5W available from the USB port to the system load with minimal power wasted as heat. This feature allows the LTC3556 to provide more power to the application and eases the constraint of thermal budgeting in small spaces. The two buck regulators can provide up to 400m A each and the buck-boost can deliver 1A. The LTC3556 is available in the low profile 28-pin (4mm × 5mm × 0.75mm) QFN surface mount package. All registered trademarks...