LTC3442 Micropower Synchronous Buck-Boost DC/DC Converter with Automatic Burst Mode Operation FEATURES DESCRIPTION n Regulated Output with Input Voltages Above, The LTC 3442 is a highly efficient, fixed frequency, buck- Below, or Equal to the Output boost DC/DC converter, which operates from input volt- n Single Inductor, No Schottky Diodes Required ages above, below, and equal to the output voltage. The n Manual or Programmable Automatic Burst Mode topology incorporated in the IC provides a continuous Operation transfer function through all operating modes, making the n Programmable Average Input Current Limit product ideal for a single lithium-ion or multicell alkaline n Up to 1.2A Continuous Output Current from a Single applications where the output voltage is within the battery Lithium-Ion Cell voltage range. n High Efficiency: Up to 95% The device includes two 0.10 N-channel MOSFET n Output Disconnect in Shutdown switches and two 0.10 P-channel switches. Operating n 2.4V to 5.5V Input Range frequency and average input current limit can each be n 2.4V to 5.25V Output Range programmed with an external resistor. Quiescent current n 35A Quiescent Current in Burst Mode Operation is only 35A in Burst Mode operation, maximizing battery n Programmable Frequency from 300kHz to 2MHz life in portable applications. Automatic Burst Mode opera- n <1A Shutdown Current tion allows the user to program the load current for Burst n Small, Thermally Enhanced 12-Lead (4mm 3mm) Mode operation, or to control it manually. DFN Package Other features include 1A shutdown current, program- APPLICATIONS mable soft-start, peak current limit and thermal shutdown. The LTC3442 is available in a low profile, thermally en- n PDA/SMART Phones hanced 12-lead (4mm 3mm 0.75mm) DFN package. n Handheld Computers L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks n MP3 Players and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 6404251, 6166527. n Handheld Instruments n Digital Cameras n Wireless Handsets n USB Peripherals TYPICAL APPLICATION Efficiency vs V IN 100 4.7H 300mA LOAD 90 SW1 SW2 V IN V OUT 1A LOAD 2.5V TO V V 3.3V IN OUT 4.2V 1.2A 1M 340k 80 LTC3442 2.2k SHDN/SS FB 70 0.01F Li-Ion 22F 15k R V LIM C 220pF 470pF 60 V = 3.3V OUT 10F L = 4.7H R BURST T F = 600kHz 0.01F SGND PGND 50 71.5k 200k 200k 2.5 3.0 3.5 4.0 4.5 5.0 5.5 V (V) IN 3442 TA01b 3442 TA01a 3442fb 1 For more information www.linear.com/LTC3442 EFFICIENCY (%)LTC3442 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Notes 1, 4) TOP VIEW V , V Voltage ............................................0.3 to 6V IN OUT SHDN/SS 1 12 FB SW1, SW2 Voltage R 2 11 V T C DC ............................................................... 0.3 to 6V SGND 3 10 R LIM Pulsed <100ns .................................................0.3 to 7V 13 PGND SW1 4 9 V IN SHDN/SS, BURST Voltage ............................... 0.3 to 6V PGND 5 8 V OUT R ...........................................................................V LIM IN SW2 6 7 BURST Operating Temperature (Note 2) ................40C to 85C Maximum Junction Temperature (Note 4) .............. 125C DE12 PACKAGE 12-LEAD (4mm 3mm) PLASTIC DFN Storage Temperature Range ....................65C to 125C T = 125C, = 53C/W 1-LAYER BOARD JMAX JA = 43C/W 4-LAYER BOARD, = 4.3C/W JA JC EXPOSED PAD (PIN 13) IS PGND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3442EDE PBF LTC3442EDE TRPBF 3442 12-Lead (4mm 3mm) Plastic DFN 40C to 85C Consult LTC Marketing for parts specified with wider operating temperature ranges. For more information on lead free part marking, go to: