Analog Devices LTC3556

Description

The LTC® 3556 is a highly integrated power management and battery charger IC for Li-Ion/Polymer battery applica- tions. It includes a high effi ciency current limited switching PowerPath manager with automatic load prioritization, a battery charger, an ideal diode, and three synchronousswitching 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 100mA or 500mA 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 400mA each and the buck-boost can deliver 1A.The LTC3556 is available in the low profi le 28-pin (4mm × 5mm × 0.75mm) QFN surface mount package.

Features

POWER MANAGER

• High Effi ciency Switching PowerPathTM Controller
• with Bat-TrackTM Adaptive Output Control
• Programmable USB or Wall Current Limit (100mA/500mA/1A)
• Full Featured Li-Ion/Polymer Battery Charger
• Instant-On Operation with a Discharged Battery
• 1.5A Maximum Charge Current
• Internal 180mΩ Ideal Diode Plus External Ideal Diode Controller Powers Load in Battery Mode
• Low No-Load IQ when Powered from BAT (<30μA)

DC/DCs

• Dual High Effi ciency Buck DC/DCs (400mA/400mA IOUT)
• High Effi ciency Buck-Boost DC/DC (1A IOUT)
• All Regulators Operate at 2.25MHz
• Dynamic Voltage Scaling on Two Buck Outputs
• I2 C Control of Enables, Mode, Two VOUT Settings
• ENALL Pin with Power-Up Sequence Control
• Low No-Load Quiescent Current: 20μA Each

Typical applications

• GPS
• Other USB-Based Handheld Products
• PDAs
• HDD-Based MP3 Players
• PMPs

More information

• Datasheet
• IC product information