LT3493 1.2A, 750kHz Step-Down Switching Regulator in 2mm × 3mm DFN FEATURESDESCRIPTION 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: <2μA Cycle-by-cycle current limit provides protection against n Low VCESAT Switch: 330mV at 1A shorted outputs and soft-start eliminates input current n Thermally Enhanced, Low Profi le DFN Package surge during start-up. The low current (<2μA) shutdown APPLICATIONS mode provides output disconnect, enabling easy power management in battery-powered systems. n Automotive Battery Regulation L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. n Industrial Control Supplies All other trademarks are the property of their respective owners. n Wall Transformer Regulation n Distributed Supply Regulation n Battery-Powered Equipment TYPICAL APPLICATIONEffi ciency3.3V Step-Down Converter 90 85 V V OUT IN V 3.3V 80 4.2V TO 36V IN BOOST 1.2A, V LT3493 0.1μF IN > 12V 10μH 0.95A, VIN > 5V 75 ON OFF SHDN SW 70 32.4k 22pF GND FB 10μF EFFICIENCY (%) 65 1μF 10k 60 VIN = 12V 55 VOUT = 3.3V 3493 TA01a L = 10μH 50 0 0.2 0.4 0.6 0.8 1.0 1.2 LOAD CURRENT (A) 3493 TA01b 3493fb 1