LT3470 Micropower Buck Regulator with Integrated Boost and Catch Diodes FeaTuresDescripTion n Low Quiescent Current: 26µA at 12VIN to 3.3VOUT The LT®3470 is a micropower step-down DC/DC con- n Integrated Boost and Catch Diodes verter that integrates a 300mA power switch, catch diode n Input Range: 4V to 40V and boost diode into low profile 3mm × 2mm DD and n Low Output Ripple: <10mV ThinSOT™ packages. The LT3470 combines Burst Mode n < 1µA in Shutdown Mode and continuous operation to allow the use of tiny induc- n Output Voltage: 1.25V to 16V tor and capacitors while providing a low ripple output to n 200mA Output Current loads of up to 200mA. n Hysteretic Mode Control With its wide input range of 4V to 40V, the LT3470 can – Low Ripple Burst Mode® Operation at Light Loads regulate a wide variety of power sources, from 2-cell Li-Ion – Continuous Operation at Higher Loads batteries to unregulated wall transformers and lead-acid n Solution Size as Small as 50mm2 batteries. Quiescent current in regulation is just 26µA in n Low Profile (0.75mm) 3mm × 2mm Thermally a typical application while a zero current shutdown mode Enhanced 8-Lead DD and 1mm ThinSOT Packages disconnects the load from the input source, simplifying power management in battery-powered systems. Fast applicaTions current limiting and hysteretic control protects the LT3470 and external components against shorted outputs, even n Automotive Battery Regulation at 40V input. n Power for Portable Products L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks n Distributed Supply Regulation and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. n Industrial Supplies n Wall Transformer Regulation Typical applicaTionEfficiency and Power Loss vs Load Current 90 1000 VIN VIN = 12V 7V TO 40V 0.22µF 80 VIN BOOST 70 100 LT3470 33µH POWER LOSS (mW) VOUT OFF ON SHDN SW 5V 60 200mA BIAS 22pF 604k 50 10 1% 2.2µF FB 22µF GND EFFICIENCY (%) 40 200k 1% 30 1 3470 TA01a 20 10 0.1 0.1 1 10 100 LOAD CURRENT (mA) 3470 TA02 3470fd 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 Revision History Related Parts