LTC3538 800mA Synchronous Buck-Boost DC/DC Converter FEATURES DESCRIPTION Regulated Output with Input Voltages Above, The LTC 3538 is a highly ef cient, low noise, buck-boost Below, or Equal to the Output DC/DC converter that operates from input voltages above, 800mA Continuous Output Current from a Single below, and equal to the output voltage. The topology Lithium-Ion/Polymer Cell incorporated in the IC provides a continuous transfer Single Inductor function through all operating modes, making the product 1.8V to 5.25V V Range ideal for single Lithium Ion or multicell Alkaline or NiMH OUT 2.4V to 5.5V V Range applications where the output voltage is within the battery IN 1MHz Fixed Frequency Operation voltage range. Output Disconnect in Shutdown The LTC3538 is suited for use in Micro Hard Disk Drive 35A Quiesecent Current in Burst Mode Operation (HDD) applications with its 800mA current capability. Burst <5A Shutdown Current Mode operation provides high ef ciency at light loads. Internal Soft-Start The LTC3538 includes two 0.17 N-channel and two Small, Thermally Enhanced 8-Lead (2mm x 3mm) 0.2 P-channel MOSFET switches. Operating frequency DFN package is internally set to 1MHz to minimize solution footprint while maximizing ef ciency. APPLICATIONS Other features include <5A shutdown current, internal Miniature Hard Disk Drives soft-start, short circuit protection and thermal shutdown. MP3 Players The LTC3538 is available in a low pro le (0.75mm), ther- Digital Cameras mally enhanced 8-lead (2mm 3mm) DFN package. Cellular Handsets , LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology PDAs, Handheld PC Corporation. All other trademarks are the property of their respective owners. Protected by GPS Receivers U.S. Patents including 5481178, 6304066, 6580258, 6166527, 6404251. TYPICAL APPLICATION Li-Ion/Polymer to 3.3V at 800mA Ef ciency vs V IN 100 L1 V = 3.3V OUT 3.3H I = 200mA LOAD V OUT 3.3V 800mA 95 LTC3538 R1 10k 464k SW1 SW2 V IN V V IN OUT 33pF 90 2.9V TO 4.2V C IN C OUT 10F FB 22F PWM BURST BURST V C 85 15k GND 330pF SD * R2 ON OFF 80 200k 2.4 2.9 3.4 3.9 4.4 4.9 5.4 V (V) IN 3538 TA01 3538 TA01b *P OPEN DRAIN I/O 3538fb 1 EFFICIENCY (%)LTC3538 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW V ,V Voltage .......................................... 0.3V to 6V IN OUT SW1,SW2 Voltage FB 1 8 V IN DC ............................................................ 0.3V to 6V VC 2 7 SW1 9 Pulsed < 100ns ........................................ 0.3V to 7V GND 3 6 SW2 BURST 5 V 4 BURST, FB, VC Voltage ................................. 0.3V to 6V OUT Operating Temperature (Note 2)............... 40C to 85C DCB PACKAGE 8-LEAD (2mm 3mm) PLASTIC DFN Maximum Junction Temperature (Note 3)............. 125C T = 125C JMAX Storage Temperature Range ................... 65C to 125C = 75C/W 4-LAYER BOARD, = 13.5C/W JA JC EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3538EDCB PBF LTC3538EDCB TRPBF LCRB 8-Lead (2mm 3mm) Plastic DFN 40C to 85C LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3538EDCB LTC3538EDCB TR LCRB 8-Lead (2mm 3mm) Plastic DFN 40C to 85C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. For more information on lead free part marking, go to: