LT3502/LT3502A 1.1MHz/2.2MHz, 500mA Step-Down Regulators in 2mm 2mm DFN and MS10 Features Description 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: <2A 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 provide protection against shorted outputs. Soft-start a 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. t ypical a LT3502A 12V Efficiency 3.3V Step-Down Converter IN 90 80 BD 5V 3.3V V OUT OUT IN V BOOST IN 4.7V TO 40V 70 1F 0.1F 6.8H V OUT 60 SW 3.3V 500mA LT3502A 50 DA 40 31.6k 30 SHDN FB OFF ON GND 20 10k 10F 10 3502 TA01a 0 0 0.1 0.2 0.3 0.4 0.5 LOAD CURRENT (A) 3502 TA01b 3502fd 1 EFFICIENCY (%) pplication pplicationsLT3502/LT3502A (Note 1) a bsolute Maxi Mu M r Input Voltage (V ) ....................................................40V BD Voltage ..................................................................7V IN BOOST Voltage .........................................................50V Operating Junction Temperature Range (Note 2) BOOST Pin Above SW Pin ...........................................7V LT3502AE, LT3502E .......................... 40C to 125C FB Voltage ...................................................................6V LT3502AI, LT3502I ............................ 40C to 125C SHDN Voltage ...........................................................40V Storage Temperature Range ..................65C to 150C p in c F TOP VIEW TOP VIEW V 1 8 SW IN SW 1 10 V IN BD 2 7 BOOST BOOST 2 9 NC 9 NC 3 8 BD FB 3 6 DA DA 4 7 FB SHDN 4 5 GND GND 5 6 SHDN MS PACKAGE DC PACKAGE 10-LEAD PLASTIC MSOP 8-LEAD (2mm 2mm) PLASTIC DFN = 110C/W JA = 102C/W JA EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB o r Der i n F M LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3502EDC PBF LT3502EDC TRPBF LCLV 8-Lead 2mm 2mm Plastic DFN 40C to 125C LT3502IDC PBF LT3502IDC TRPBF LCLV 8-Lead 2mm 2mm Plastic DFN 40C to 125C LT3502AEDC PBF LT3502AEDC TRPBF LCLT 8-Lead 2mm 2mm Plastic DFN 40C to 125C LT3502AIDC PBF LT3502AIDC TRPBF LCLT 8-Lead 2mm 2mm Plastic DFN 40C to 125C LT3502EMS PBF LT3502EMS TRPBF LTDTR 10-Lead Plastic MSOP 40C to 125C LT3502IMS PBF LT3502IMS TRPBF LTDTR 10-Lead Plastic MSOP 40C to 125C LT3502AEMS PBF LT3502AEMS TRPBF LTDTS 10-Lead Plastic MSOP 40C to 125C LT3502AIMS PBF LT3502AIMS TRPBF LTDTS 10-Lead Plastic MSOP 40C to 125C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: