LTC3557/LTC3557-1 USB Power Manager with Li-Ion Charger and Three Step-Down Regulators FEATURES DESCRIPTION Seamless Transition Between Input Power Sources: The LTC 3557/LTC3557-1 is a highly integrated power Li-Ion Battery, USB, 5V Wall Adapter or High management and battery charger IC for single cell Li-Ion/ TM TM Voltage Buck Regulator with Bat-Track Polymer battery applications. It includes a PowerPath 200m Internal Ideal Diode Plus Optional External manager with automatic load prioritization, a battery Ideal Diode Controller Provides Low Loss Power charger, an ideal diode and numerous internal protection Path When Input Current is Limited or Unavailable features. Designed speci cally for USB applications, the Triple Adjustable High Ef ciency Step-Down LTC3557/LTC3557-1 power manager automatically limits Switching Regulators (600mA, 400mA, 400mA I ) input current to a maximum of either 100mA or 500mA OUT Pin Selectable Burst Mode Operation for USB applications or 1A for wall adapter powered Full Featured Li-Ion/Polymer Battery Charger applications. Battery charge current is automatically 1.5A Maximum Charge Current with Thermal Limiting reduced such that the sum of the load current and the Battery Float Voltage: charge current does not exceed the programmed input 4.2V (LTC3557) current limit. The LTC3557/LTC3557-1 also includes three 4.1V (LTC3557-1) adjustable synchronous step-down switching regulators Low Pro le 4mm 4mm 28-Pin QFN Package and a high voltage buck regulator output controller with Bat-Track that allows ef cient charging from supplies as high as 38V. The LTC3557/LTC3557-1 is available in a low APPLICATIONS pro le 4mm 4mm 0.75mm 28-pin QFN package. HDD-Based MP3 Players , LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology PDA, PMP, PND/GPS Corporation. Bat-Track and PowerPath are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. USB-Based Handheld Products Protected by U.S. Patents, including 6522118, 6700364. Other patents pending. TYPICAL APPLICATION Input and Battery Current vs Load Current HV SUPPLY HIGH VOLTAGE 8V TO 38V BUCK DC/DC (TRANSIENTS 600 R = 2k PROG TO 60V) R = 2k I CLPROG IN 500 100mA/500mA 1000mA 400 USB OR V I OUT LOAD 5V ADAPTER 0V 300 CC/CV I CHARGER BAT 200 CHARGE + SINGLE CELL (CHARGING) Li-Ion NTC LTC3557/LTC3557-1 100 ALWAYS ON LDO 3.3V/25mA 0 I BAT (DISCHARGING) WALL = 0V 0.8V to 3.6V/600mA 100 TRIPLE HIGH EFFICIENCY 0 100 200 300 400 500 600 RST STEP-DOWN 0.8V to 3.6V/400mA SWITCHING REGULATORS I (mA) LOAD 0.8V to 3.6V/400mA 35571 TA01b 35571 TA01a 35571fc 1 CURRENT (mA)LTC3557/LTC3557-1 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Notes 1-4) V , V , V , V BUS OUT IN1 IN2 TOP VIEW t < 1ms and Duty Cycle < 1% .................. 0.3V to 7V Steady State ............................................. 0.3V to 6V 28 27 26 25 24 23 22 BAT, NTC, CHRG, WALL, V , C 1 ILIM0 21 GATE MODE, FB1, FB2, FB3, RST2 ........................ 0.3V to 6V ILIM1 2 20 PROG EN1, EN2, EN3 .............................. 0.3V to V + 0.3V OUT WALL 3 19 NTC ILIM0, ILIM1, PROG ....................... 0.3V to V + 0.3V CC LDO3V3 4 29 18 V NTC I , I , I .........................................................2A VBUS VOUT BAT SW1 5 17 SW3 I .....................................................................850mA V 6 16 V SW1 IN1 IN2 I , I ............................................................600mA FB1 7 15 SW2 SW2 SW3 I , I , I .................................................75mA 8 9 10 11 12 13 14 RST2 CHRG ACPR I , I .......................................................... 2mA CLPROG PROG Maximum Operating Junction Temperature .......... 110C UF PACKAGE 28-LEAD (4mm 4mm) PLASTIC QFNs Operating Ambient Temperature Range ...40C to 85C T = 110C, = 37C/W JMAX JA Storage Temperature Range ...................65C to 125C EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3557EUF PBF LTC3557EUF TRPBF 3557 28-Lead (4mm 4mm) Plastic QFN 40C to 85C LTC3557EUF-1 PBF LTC3557EUF-1 TRPBF 35571 28-Lead (4mm 4mm) Plastic QFN 40C to 85C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based nish parts. For more information on lead free part marking, go to: