LT3502/LT3502A 1.1MHz/2.2MHz, 500mA Step-Down Regulators in 2mm × 2mm DFN and MS10 FeaturesDescription n 3V to 40V Input Voltage Range The LT®3502/LT3502A are current mode PWM step-down n 500mA Output Current DC/DC converters with an internal 500mA power switch, n Switching Frequency: 2.2MHz (LT3502A), in tiny 8-lead 2mm × 2mm DFN and 10-lead MS10 1.1MHz (LT3502) packages. The wide input voltage range of 3V to 40V makes n 800mV Feedback Voltage the LT3502/LT3502A suitable for regulating power from a n Short-Circuit Robust wide variety of sources, including 24V industrial supplies n Soft-Start and automotive batteries. Its high operating frequency n Low Shutdown Current: <2µA allows the use of tiny, low cost inductors and capacitors, n Internally Compensated resulting in a very small solution. Constant frequency n Internal Boost Diode above the AM band avoids interfering with radio reception, n Thermally Enhanced 2mm × 2mm 8-Lead DFN making the LT3502A particularly suitable for automotive and 10-Lead MS10 Package applications. Cycle-by-cycle current limit and frequency foldback applications provide protection against shorted outputs. Soft-start and frequency foldback eliminates input current surge n Automotive Systems during start-up. DA current sense provides further protec- n Battery-Powered Equipment tion in fault conditions. An internal boost diode reduces n Wall Transformer Regulation component count. n Distributed Supply Regulation L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. typical application3.3V Step-Down ConverterLT3502A 12VIN Efficiency 90 BD 80 VIN V 5VOUT 3.3VOUT IN BOOST 4.7V TO 40V 70 1µF 0.1µF 6.8µH VOUT 60 SW 3.3V LT3502A 500mA 50 DA 40 31.6k EFFICIENCY (%) 30 OFF ON SHDN FB GND 10k 10µF 20 10 3502 TA01a 0 0 0.1 0.2 0.3 0.4 0.5 LOAD CURRENT (A) 3502 TA01b 3502fd 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts