LTC3456 Datasheet | Linear Technology

2-Cell, Multi-Output DC/DC Converter with USB Power Manager Features - Seamless Transition Between 2-Cell Battery, USB and AC Wall Adapter Input Power Sources - Main Output: Fixed 3.3V Output - Core Output: Adjustable from 0.8V to VBATT(MIN) - Hot Swap TM Output for Memory Cards - All Outputs Discharged to Ground During Shutdown - Power Supply Sequencing: Main and Hot Swap Outputs e Up After Core Output - Accurate USB Current Limiting - High Frequency Operation: 1MHz - High Efficiency: Up to 92% - Small (4mm × 4mm × 0.75mm) 24-Pin QFN Package U APPLICATIO S - GPS Portable Navigators - MP3 Players - Digital Cameras - Handheld puters DESCRIPTIO The LTC®3456 is a plete power management system IC optimized for a variety of portable applications. The device generates two separate power rails: a 3.3V (fixed) Main supply and a 1.8V (adjustable) Core supply. In addition, the LTC3456 contains a USB power manager, a Hot Swap output, a low-battery indicator and an alwaysalive VMAX output. The LTC3456 takes power from one of three sources: a Wall adapter, a USB port or a 2-cell Alkaline/Ni Cd/Ni MH battery, in that order of priority. Current drawn from the USB port is accurately limited to 100m A or 500m A based on the state of the USBHP pin. The Main and Core switchers are all high efficiency, 1MHz fixed frequency PWM converters. Availability in a small (4mm × 4mm × 0.75mm) 24-pin QFN package makes the LTC3456 ideal for space-sensitive portable devices. , LTC and LT are registered trademarks of Linear Technology Corporation. Hot Swap is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 6580258, 6304066. POWER LOSS (m W) TYPICAL APPLICATIO 2 AA + CELLS 4.7µF L2 4.7µH L3...