POWER LOSS (mW) LTC3552-1 Standalone Linear Li-Ion Battery Charger and Dual Synchronous Buck Converter FEATURES DESCRIPTIO Programmable Charge Current Up to 950mA The LTC 3552-1 is a complete constant-current/constant- Complete Linear Charger and Dual DC/DC voltage linear charger and dual xed output DC/DC con- Regulator verter for single cell lithium-ion batteries. Its DFN package Dual Fixed Outputs: and low external component count make the LTC3552-1 1.8V at 800mA ideally suited for portable applications. Furthermore, 1.575V at 400mA the LTC3552-1 is designed to work within USB power No MOSFET, Sense Resistor or Blocking Diode speci cations. Required No external sense resistor or external blocking diode are Thermal Regulation Maximizes Charge Rate required due to the internal MOSFET architecture. The Without Risk of Overheating* charge voltage is xed at 4.2V and the charge current is Charges Directly from a USB Port programmed with a resistor. The charge cycle terminates Programmable Charge Current Termination when the charge current drops below the programmed Preset 4.2V Charge Voltage with 1% Accuracy termination threshold after the nal oat voltage is Charge Current Monitor Output for Gas Gauging* reached. When the input supply (wall adapter or USB Automatic Recharge supply) is removed, the LTC3552-1 enters a low current Charge Status Output state dropping the battery drain current to less than 2A. Power Present Output Thermal regulation maximizes charge rate without risk Soft-Start Limits Inrush Current of overheating. Low Quiescent Current Buck Converter (40A) The synchronous step-down switching regulators Current Mode Operation, Constant Frequency (2.25MHz) generate xed output voltages of 1.8V and 1.575V. Low Pro le (5mm 3mm 0.75mm) DFN Package The switching frequency is set at 2.25MHz, allowing the U use of small surface mount inductors and capacitors. APPLICATIO S , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Cellular Telephones, PDAs, MP3 Players Burst Mode is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Bluetooth Applications Protected by U.S. Patents including 6522118, 6700364, 5481178, 6580258, 6304066, 6127815, 6498466, 6611131. TYPICAL APPLICATIO Ef ciency Curve/ Power Loss of Regulators Single Cell Li-Ion Battery Charger with 100 1000 C/5 Termination and Dual DC/DC Converter 95 V = 1.575V OUT2 V V IN IN RUN1 90 100 V = 1.8V OUT1 4.5V TO ITERM 1F 800mA 6.5V RUN2 85 PROG 4.2V + 1-CELL 619 1.24k BAT 10F CHRG 80 10 Li-Ion CHANNEL 1 BATTERY PWR V CC 75 LTC3552-1 EN 4.7H 2.2H V V OUT2 OUT1 CHANNEL 2 1.575V/ SW2 SW1 1.8V/ 70 1 400mA 800mA V V OUT2 OUT1 C C 65 C C OUT2 OUT1 V = 3.6V FF2 FF1 IN 10F 10F 330pF 330pF Burst Mode OPERATION V V CER CER 60 0.1 FB2 FB1 GND 1 10 100 1000 35521 TA01 LOAD CURRENT (mA) 35521 TAO1b 35521fa 1 EFFICIENCY (%) U ULTC3552-1 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW Input Supply Voltage (V ) ......................... 0.3V to 10V IN ITERM 1 16 EN PROG, ITERM .................................. 0.3V to V + 0.3V IN BAT 2 15 PWR BAT .............................................................. 0.3V to 7V CHRG 3 14 V IN CHRG, PWR, EN ....................................... 0.3V to 10V RUN2 4 13 PROG BAT Short-Circuit Duration ............................Continuous 17 SW2 5 12 SW1 BAT Pin Current ..........................................................1A RUN1 6 11 V CC PROG Pin Current ....................................................1mA V 7 10 V OUT2 OUT1 V Supply Voltage ...................................... 0.3V to 6V CC V 8 9 V FB2 FB1 V , V , RUN1, OUT1 OUT2 DHC PACKAGE RUN2 Voltages .............................0.3V to V +0.3V CC 16-LEAD (5mm 3mm) PLASTIC DFN V , V ........................................0.3V to V + 0.3V FB1 FB2 CC T = 125C, = 40C/W (Note 3) JMAX JA EXPOSED PAD IS GROUND (PIN 17) MUST BE SOLDERED TO PCB SW1, SW2 Voltage ...........................0.3V to V + 0.3V CC Ambient Operating Temperature ORDER PART NUMBER DHC PART MARKING Range (Note 2) .................................... 40C to 85C LTC3552EDHC-1 35521 Maximum Junction Temperature (Note 8) ............ 125C Order Options Tape and Reel: Add TR Storage Temperature Range ................... 65C to 125C Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: