LT3493 1.2A, 750kHz Step-Down Switching Regulator in 2mm 3mm DFN FEATURES DESCRIPTION n Wide Input Range: 3.6V to 36V Operating, The LT 3493 is a current mode PWM step-down DC/DC 40V Maximum converter with an internal 1.75A power switch. The wide n 1.2A Output Current operating input range of 3.6V to 36V (40V maximum) n Fixed Frequency Operation: 750kHz makes the LT3493 ideal for regulating power from a wide n Output Adjustable Down to 780mV variety of sources, including unregulated wall transform- n Short-Circuit Robust ers, 24V industrial supplies and automotive batteries. n Uses Tiny Capacitors and Inductors Its high operating frequency allows the use of tiny, low n Soft-Start cost inductors and ceramic capacitors, resulting in low, n Internally Compensated predictable output ripple. n Low Shutdown Current: <2A Cycle-by-cycle current limit provides protection against n Low V Switch: 330mV at 1A CESAT shorted outputs and soft-start eliminates input current n Thermally Enhanced, Low Pro le DFN Package surge during start-up. The low current (<2A) shutdown mode provides output disconnect, enabling easy power APPLICATIONS management in battery-powered systems. n Automotive Battery Regulation L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. n Industrial Control Supplies n Wall Transformer Regulation n Distributed Supply Regulation n Battery-Powered Equipment TYPICAL APPLICATION Ef ciency 90 3.3V Step-Down Converter 85 V OUT V IN 80 V BOOST 3.3V IN 4.2V TO 36V 1.2A, V > 12V IN 0.1F LT3493 10H 75 0.95A, V > 5V IN SW ON OFF SHDN 70 32.4k 22pF GND FB 65 10F 10k 1F 60 V = 12V IN 55 V = 3.3V OUT 3493 TA01a L = 10H 50 0 0.2 0.4 0.6 0.8 1.0 1.2 LOAD CURRENT (A) 3493 TA01b 3493fb 1 EFFICIENCY (%)LT3493 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW Input Voltage (V ) .................................................... 40V IN BOOST Pin Voltage ..................................................50V FB 1 6 SHDN BOOST Pin Above SW Pin .........................................25V GND 7 5 V 2 IN SHDN Pin ..................................................................40V BOOST 4 SW 3 FB Voltage ...................................................................6V Operating Temperature Range (Note 2) DCB PACKAGE 6-LEAD (2mm 3mm) PLASTIC DFNs LT3493E .............................................. 40C to 85C T = 125C, = 64C/W JMAX JA LT3493I ............................................. 40C to 125C EXPOSED PAD (PIN 7) IS GND, MUST BE SOLDERED TO PCB Maximum Junction Temperature .......................... 125C Storage Temperature Range ................... 65C to 150C ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT3493EDCB PBF LT3493EDCB TRPBF LCGG 6-Lead (2mm 3mm) Plastic DFN 40C to 85C LT3493IDCB PBF LT3493IDCB TRPBF LCGH 40C to 125C 6-Lead (2mm 3mm) Plastic DFN LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT3493EDCB LT3493EDCB TR LCGG 6-Lead (2mm 3mm) Plastic DFN 40C to 85C LT3493IDCB LT3493IDCB TR LCGH 6-Lead (2mm 3mm) Plastic DFN 40C to 125C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. For more information on lead free part marking, go to: