POWER LOSS (mW) LTC3456 2-Cell, Multi-Output DC/DC Converter with USB Power Manager FEATURES DESCRIPTIO Seamless Transition Between 2-Cell Battery, USB The LTC 3456 is a complete power management system and AC Wall Adapter Input Power Sources IC optimized for a variety of portable applications. The Main Output: Fixed 3.3V Output device generates two separate power rails: a 3.3V (fixed) Core Output: Adjustable from 0.8V to V Main supply and a 1.8V (adjustable) Core supply. In BATT(MIN) TM Hot Swap Output for Memory Cards addition, the LTC3456 contains a USB power manager, a All Outputs Discharged to Ground During Shutdown Hot Swap output, a low-battery indicator and an always- Power Supply Sequencing: Main and Hot Swap alive V output. The LTC3456 takes power from one of MAX Outputs Come Up After Core Output three sources: a Wall adapter, a USB port or a 2-cell Accurate USB Current Limiting Alkaline/NiCd/NiMH battery, in that order of priority. Cur- High Frequency Operation: 1MHz rent drawn from the USB port is accurately limited to High Efficiency: Up to 92% 100mA or 500mA based on the state of the USBHP pin. Small (4mm 4mm 0.75mm) 24-Pin QFN Package The Main and Core switchers are all high efficiency, 1MHz U fixed frequency PWM converters. Availability in a small APPLICATIO S (4mm 4mm 0.75mm) 24-pin QFN package makes the LTC3456 ideal for space-sensitive portable devices. GPS Portable Navigators , LTC and LT are registered trademarks of Linear Technology Corporation. MP3 Players 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, Digital Cameras 6580258, 6304066. Handheld Computers TYPICAL APPLICATIO V INT 3.3V + 2 AA 22F Efficiency and Power Loss 4.7F L2 L3 CELLS 4.7H 10H vs Load Current (Battery Powered) 100k V SW2 BST SW2 BK V BATT INT MAIN OUTPUT 100 250 3.3V AIN V MAIN V = 2.4V BATT 150mA 1F 80.6k 90 MODE = 0V AO Hot Swap OUTPUT 80 200 3.3V HSO 1.8V 3.3V USBHP 70 USB POWER USB 50mA OUTPUT OUTPUT 1F L1 CONTROLLER (4.35V TO 5.5V) SUSPEND 60 150 4.7F 10H CORE OUTPUT EFFICIENCY 50 SW1 1.8V LTC3456 1 USB 200mA 10F 3.3V 40 100 1k OUTPUT POWER LOSS 100k EXT PWR 30 AC WALL 220pF ADAPTER V EXT FB1 20 50 (5V 10%) 4.7F 1.8V 10F 11.3k 80.6k 10 OUTPUT 1 V MAX WALLFB 0 0 V (POWERS MAX 1 10 100 1000 PWRKEY 4.32k REAL-TIME CLOCK) 1F LOAD CURRENT (mA) PBSTAT RESET MODE PWRON PGND AGND ON/OFF 3456 TA01b 3456 TA01 P 3456fa 1 EFFICIENCY (%) U ULTC3456 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW ORDER PART V , V Voltages ................................. 0.3V to 6V BATT MAX NUMBER V , V , V , HSO Voltages ................ 0.3V to 6V INT MAIN EXT SW1, SW2 BK, SW2 BST Voltages ........... 0.3V to 6V 24 23 22 21 20 19 LTC3456EUF AIN 1 18 SUSPEND USB, USBHP, SUSPEND Voltages .............. 0.3V to 6V AO 2 17 HSO PWRKEY, PBSTAT, PWRON Voltages ........ 0.3V to 6V AGND V 3 16 MAIN 25 MODE, AO, EXT PWR, RESET Voltages ..... 0.3V to 6V V 4 15 V BATT INT SW1 5 14 SW2 BST FB1, AIN, WALLFB Voltages ....................... 0.3V to 2V PGND 6 13 SW2 BK Junction Temperature.......................................... 125C UF PART 7 8 9 10 11 12 Operating Temperature Range (Note 2) .. 40C to 85C MARKING Storage Temperature Range ................. 65C to 125C 3456 UF PACKAGE 24-LEAD (4mm 4mm) PLASTIC QFN T = 125C, = 37C/ W, = 2C/ W JMAX JA JC EXPOSED PAD (PIN 25) IS PGND MUST BE SOLDERED TO PCB Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: