DC1037A Analog Devices

POWER LOSS (mW) LT3470 Micropower Buck Regulator with Integrated Boost and Catch Diodes FEATURES DESCRIPTION n Low Quiescent Current: 26A at 12V to 3.3V The LT 3470 is a micropower step-down DC/DC con- IN OUT 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 <1A 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 2 n Solution Size as Small as 50mm batteries. Quiescent current in regulation is just 26A 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 n AEC-Q100 Qualified for Automotive Applications power management in battery-powered systems. Fast current limiting and hysteretic control protects the LT3470 and external components against shorted outputs, even APPLICATIONS at 40V input. n Automotive Battery Regulation All registered trademarks and trademarks are the property of their respective owners. n Power for Portable Products n Distributed Supply Regulation n Industrial Supplies n Wall Transformer Regulation TYPICAL APPLICATION Efficiency and Power Loss vs Load Current 90 1000 V IN V = 12V IN 7V TO 40V 0.22F 80 V BOOST IN 70 100 LT3470 33H V OUT OFF ON SHDN SW 5V 60 200mA BIAS 604k 50 10 22pF 1% FB 2.2F 22F 40 GND 200k 1% 30 1 3470 TA01a 20 10 0.1 0.1 1 10 100 LOAD CURRENT (mA) 3470 TA02 Rev. E 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LT3470 ABSOLUTE MAXIMUM RATINGS (Note 1) V , SHDN Voltage ................................................... 40V Operating Temperature Range (Note 2) IN BOOST Pin Voltage .................................................. 47V LT3470E ...............................................40C to 85C BOOST Pin Above SW Pin ........................................ 25V LT3470I ............................................. 40C to 125C FB Voltage .................................................................. 5V LT3470H ............................................ 40C to 150C BIAS Voltage .............................................................25V Storage Temperature Range .................. 65C to 150C SW Voltage ................................................................V Lead Temperature (Soldering, 10 sec) ..................300C IN Maximum Junction Temperature LT3470E, LT3470I ............................................. 125C LT3470H ........................................................... 150C PIN CONFIGURATION TOP VIEW TOP VIEW FB 1 8 SHDN SHDN 1 8 FB BIAS 2 7 NC NC 2 7 BIAS 9 BOOST 3 6 V IN V 3 6 BOOST IN SW GND 4 5 GND 4 5 SW TS8 PACKAGE 8-LEAD PLASTIC TSOT-23 DDB8 PACKAGE 8-LEAD (3mm 2mm) PLASTIC DFN = 140C/W JA = 180C/W JA EXPOSED PAD (PIN 9) IS GROUND (MUST BE SOLDERED TO PCB) ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT3470EDDB TRMPBF LT3470EDDB TRPBF LBPN 8-Lead (3mm 2mm) Plastic DFN 40C to 85C LT3470IDDB TRMPBF LT3470IDDB TRPBF LBPP 40C to 125C 8-Lead (3mm 2mm) Plastic DFN LT3470HDDB TRMPBF LT3470HDDB TRPBF LCNR 8-Lead (3mm 2mm) Plastic DFN 40C to 150C LT3470ETS8 PBF LT3470ETS8 TRPBF LTBDM 8-Lead Plastic TSOT-23 40C to 85C LT3470ITS8 PBF LT3470ITS8 TRPBF LTBPW 8-Lead Plastic TSOT-23 40C to 125C LT3470HTS8 PBF LT3470HTS8 TRPBF LTCNQ 8-Lead Plastic TSOT-23 40C to 150C LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT3470EDDB LT3470EDDB TR LBPN 8-Lead (3mm 2mm) Plastic DFN 40C to 85C LT3470IDDB LT3470IDDB TR LBPP 8-Lead (3mm 2mm) Plastic DFN 40C to 125C LT3470HDDB LT3470HDDB TR LCNR 8-Lead (3mm 2mm) Plastic DFN 40C to 150C LT3470ETS8 LT3470ETS8 TR LTBDM 8-Lead Plastic TSOT-23 40C to 85C LT3470ITS8 LT3470ITS8 TR LTBPW 8-Lead Plastic TSOT-23 40C to 125C LT3470HTS8 LT3470HTS8 TR LTCNQ 8-Lead Plastic TSOT-23 40C to 150C Rev. E 2 For more information www.analog.com