LTC3443 High Current Micropower 600kHz Synchronous Buck-Boost DC/DC Converter FEATURES DESCRIPTIO The LTC 3443 is a high efficiency, fixed frequency, buck- Regulated Output with Input Above, Below or Equal boost DC/DC converter that operates from input voltages to the Output above, below or equal to the output voltage. The part is pin Single Inductor, No Schottky Diodes for pin compatible with its predecessor, the LTC3441, with High Efficiency: Up to 96% a lower operating frequency (600kHz), and a V pin clamp C 28 A Quiescent Current in Burst Mode Operation circuit during Burst Mode operation. The topology incor- Up to 1.2A Continuous Output Current from a Single porated in the IC provides a continuous transfer function Lithium-Ion through all operating modes, making the product ideal for True Output Disconnect in Shutdown single Lithium Ion or multicell applications where the out- 2.4V to 5.5V Input Range put voltage is within the battery voltage range. 2.4V to 5.25V Output Range 600kHz Fixed Frequency Operation The device includes two 0.10 N-channel MOSFET switches and two 0.11 P-channel switches. External Synchronizable Oscillator Schottky diodes are optional, and can be used for a Selectable Burst Mode or Fixed Frequency Operation moderate efficiency improvement. The operating frequency <1 A Quiescent Current in Shutdown is internally set to 600kHz and can be synchronized up to Small, Thermally Enhanced 12-Lead 1.2MHz. Quiescent current is only 28 A in Burst Mode (4mm 3mm 0.8mm) DFN package operation, maximizing battery life in portable applications. U Burst Mode operation is user controlled and can be APPLICATIO S enabled by driving the MODE/SYNC pin high. If the MODE/ Handheld Computers SYNC pin is driven low or with a clock, then fixed fre- Handheld Instruments quency switching is enabled. MP3 Players Other features include a 1A shutdown, soft-start control, Digital Cameras thermal shutdown and current limit. The LTC3443 is , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. available in a thermally enhanced 12-lead (4mm 3mm) All other trademarks are the property of their respective owners. Burst Mode is a registered trademark of Linear Technology Corporation. DFN Package. U.S. Patent s 6404251, 6166527 TYPICAL APPLICATIO Efficiency vs V IN Li-Ion to 3.3V at 1A Buck-Boost Converter 100 I = 200mA 6H V OUT OUT 95 3.3V 1A 220pF 90 SW1 SW2 340k I = 1A 85 OUT PV V IN OUT V IN 2.2k 80 LTC3443 2.5V V FB 44F IN 15k 75 TO 4.2V (2 22F) SHDN/SS V C 70 MODE/SYNC GND 560pF Li-Ion 65 200k 10F PGND PGND 60 55 V = 3.3V OUT 3443 TA01 50 2.7 3.2 3.7 4.2 4.7 5.2 V (V) 3443 TA02 IN 3443fa 1 EFFICIENCY (%) U ULTC3443 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) ORDER PART V , V Voltage........................................ 0.3V to 6V TOP VIEW IN OUT NUMBER SW1, SW2 Voltage SHDN/SS 1 12 FB DC ...........................................................0.3V to 6V GND 2 11 V LTC3443EDE C Pulsed < 100ns ...................................... 0.3V to 7V PGND 3 10 V IN 13 SHDN/SS, MODE/SYNC Voltage ................. 0.3V to 6V SW1 4 9 PV IN Operating Temperature Range (Note 2) .. 40C to 85C SW2 5 8 V OUT Maximum Junction Temperature (Note 4) ........... 125C PGND 6 7 MODE/SYNC Storage Temperature Range ................ 65C to 125C DE PART MARKING DE12 PACKAGE 12-LEAD (4mm 3mm) PLASTIC DFN 3443 T = 125C JMAX = 53C/W 1-LAYER BOARD JA = 43C/W 4-LAYER BOARD JA = 4.3C/W JC EXPOSED PAD IS PGND (PIN 13) MUST BE SOLDERED TO PCB Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: