LTC3550 Dual Input USB/AC Adapter Li-Ion Battery Charger with 600mA Buck Converter FEATURES DESCRIPTIO Charges Single-Cell Li-Ion Battery from Wall The LTC 3550 is a standalone linear charger with a 600mA Adapter and USB Inputs monolithic synchronous buck converter. It is capable of Automatic Input Power Detection and Selection charging a single-cell Li-Ion battery from both wall adapter Charge Current Programmable Up to 950mA from and USB inputs. The charger automatically selects the Wall Adapter Input appropriate power source for charging. Adjustable Output, High Ef ciency 600mA Internal thermal feedback regulates the battery charge Synchronous DC/DC Converter current to maintain a constant die temperature during high No External MOSFET, Sense Resistor or Blocking power operation or high ambient temperature conditions. Diode Needed The oat voltage is xed at 4.2V and the charge currents Thermal Regulation Maximizes Charge Rate Without are programmed with external resistors. The LTC3550 Risk of Overheating* terminates the charge cycle when the charge current Preset Charge Voltage with 0.6% Accuracy drops below the programmed termination threshold after Programmable Charge Current Termination the nal oat voltage is reached. With power applied to 1.5MHz Constant Frequency Operation (Step-Down both inputs, the LTC3550 can be put into shutdown mode Converter) reducing the DCIN supply current to 20A, the USBIN 18A USB Suspend Current in Shutdown supply current to 10A, and the battery drain current to Power Present Status Output less than 2A. Charge Status Output The DC/DC converter switching frequency is internally Automatic Recharge set at 1.5MHz, allowing the use of small surface mount Available in a Thermally Enhanced, Low Pro le inductors and capacitors. (0.75mm) 16-Lead (5mm 3mm) DFN Package , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. U All other trademarks are the property of their respective owners. APPLICATIO S *Protected by U.S. patents, includng 6522118, 6700364, 6580258, 5481178, 6304066, 6127815, 6498466, 6611131 Cellular Telephones TYPICAL APPLICATIO Complete Charge Cycle (1100mA Battery) 1000 Dual Input Battery Charger and DC/DC Converter 800 600 2.2H V OUT 400 1.2V SW 200 600mA C OUT 0 CONSTANT VOLTAGE LTC3550 10F 22pF 301k 4.2 CER WALL 4.0 DCIN V FB ADAPTER USBIN = 5V 3.8 RUN 301k T = 25C A 3.6 USB 800mA (WALL) R = 1.24k USBIN V IDC CC 3.4 PORT 500mA (USB) R = 2k IUSB 1F IUSB BAT 5.0 2k 2.5 4.7F ITERM IDC 1% 4.2V 0 + 1F GND 1.24k 2k SINGLE-CELL 1% 1% Li-Ion BATTERY 0 0.5 1.0 1.5 2.0 2.5 3.0 TIME (HR) 3550 TA01 3550 TA02 3550fa 1 DCIN BATTERY CHARGE VOLTAGE (V) VOLTAGE (V) CURRENT (mA) U ULTC3550 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW DCIN, USBIN .............................................. 0.3V to 10V USBIN 1 16 DCIN EN, CHRG, PWR, HPWR ............................ 0.3V to 10V IUSB 2 15 BAT BAT, IDC, IUSB, ITERM ................................ 0.3V to 7V ITERM 3 14 IDC V ............................................................... 0.3V to 6V CC PWR 4 13 HPWR RUN, V .....................................................0.3V to V 17 FB CC CHRG 5 12 EN SW (DC) ........................................0.3V to (V + 0.3V) CC V 6 11 RUN FB DCIN Pin Current (Note 2) ..........................................1A V 7 10 SW CC USBIN Pin Current (Note 2) .................................700mA GND 8 9 GND BAT Pin Current (Note 2) ............................................1A DHC PACKAGE P-Channel SW Source Current (DC) .....................800mA 16-LEAD (5mm 3mm) PLASTIC DFN T = 125C, = 40C (NOTE 4) N-Channel SW Source Current (DC) ....................800mA JMAX JA EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB Peak SW Sink and Source Current ...........................1.3A Operating Temperature Range (Note 3) ... 40C to 85C ORDER PART NUMBER DHC PART MARKING Maximum Junction Temperature .......................... 125C LTC3550EDHC 3550 Storage Temperature Range ................... 65C to 125C Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: