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 SwapTM Output for Memory Cards
All Outputs Discharged to Ground During Shutdown
Power Supply Sequencing: Main and Hot Swap
Outputs Come 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
ApplicationGPS Portable Navigators
MP3 Players
Digital Cameras
Handheld ComputersPinout
SpecificationsV BATT, V MAX Voltages .................................... 0.3V to 6V
VINT , V MAIN, V MAIN, HSO Voltages ................ 0.3V to 6V
SW1, SW2_BK, SW2_BST Voltages.................. 0.3V to 6V
USB, USBHP, SUSPEND Voltages ..................... 0.3V to 6V
PWRKEY, PBSTAT, PWRON Voltages ................ 0.3V to 6V
MODE, AO, EXT_PWR, RESET Voltages............. 0.3V to 6V
FB1, AIN, WALLFB Voltages ............................. 0.3V to 2V
Junction Temperature.............................................. 125°C
Operating Temperature Range (Note 2).. 40°C to 85°C
Storage Temperature Range................. 65°C to 125°CDescription
The LTC(R) 3456 is a complete 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 always- alive VMAX output. The LTC3456 takes power from one of three sources: a Wall adapter, a USB port or a 2-cell Alkaline/NiCd/NiMH battery, in that order of priority. Cur- rent drawn from the USB port is accurately limited to 100mA or 500mA 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.
LTC3456 Data Sheet
