LT3480 36V, 2A, 2.4MHz Step-Down Switching Regulator with 70A Quiescent Current FEATURES DESCRIPTION n Wide Input Range: The LT 3480 is an adjustable frequency (200kHz to Operation from 3.6V to 36V 2.4MHz) monolithic buck switching regulator that ac- Over-Voltage Lockout Protects Circuits cepts input voltages up to 36V (60V maximum). A high through 60V Transients efficiency 0.25 switch is included on the die along with n 2A Maximum Output Current a boost Schottky diode and the necessary oscillator, con- n Low Ripple Burst Mode Operation trol, and logic circuitry. Current mode topology is used 70A I at 12V to 3.3V for fast transient response and good loop stability. Low Q IN OUT Output Ripple < 15mV ripple Burst Mode operation maintains high efficiency at n Adjustable Switching Frequency: 200kHz to 2.4MHz low output currents while keeping output ripple below n Low Shutdown Current: I < 1A 15mV in a typical application. In addition, the LT3480 can Q n Integrated Boost Diode further enhance low output current efficiency by draw - n Synchronizable Between 250kHz to 2MHz ing bias current from the output when V is above 3V. OUT n Power Good Flag Shutdown reduces input supply current to less than 1A n Saturating Switch Design: 0.25 On-Resistance while a resistor and capacitor on the RUN/SS pin provide a n 0.790V Feedback Reference Voltage controlled output voltage ramp (soft-start). A power good n Output Voltage: 0.79V to 20V flag signals when V reaches 86% of the programmed OUT n Soft-Start Capability output voltage. The LT3480 is available in 10-lead MSOP n Small 10-Lead Thermally Enhanced MSOP and and 3mm 3mm DFN packages with exposed pads for (3mm 3mm) DFN Packages low thermal resistance. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. All other APPLICATIONS trademarks are the property of their respective owners. n Automotive Battery Regulation n Power for Portable Products n Distributed Supply Regulation n Industrial Supplies TYPICAL APPLICATION 3.3V Step-Down Converter Efficiency V V 100 IN OUT 4.5V TO 36V 3.3V TRANSIENT 2A V = 5V V BD OUT IN TO 60V 90 RUN/SS BOOST OFF ON V = 3.3V OUT 0.47F 80 4.7H 14k V LT3480 SW C 4.7F 70 RT 470pF PG 60 316k 40.2k V = 12V SYNC FB IN GND L = 5.6H F = 800 kHz 100k 22F 50 0 0.5 1.0 1.5 2 LOAD CURRENT (A) 3480 TA01 3480 TA01b 3480fe 1 For more information www.linear.com/LT3480 EFFICIENCY (%)LT3480 (Note 1) ABSOLUTE MAXIMUM RATINGS V , RUN/SS Voltage (Note 5) ...................................60V Storage Temperature Range ................... 65C to 150C IN BOOST Pin Voltage ...................................................56V Lead Temperature (Soldering, 10 sec) BOOST Pin Above SW Pin .........................................30V (MSE Only) ....................................................... 300C FB, RT, V Voltage .......................................................5V C PG, BD, SYNC Voltage ..............................................30V Operating Junction Temperature Range (Note 2) LT3480E ............................................. 40C to 125C LT3480I .............................................. 40C to 125C LT3480H ............................................ 40C to 150C LT3480MP.......................................... 55C to 150C PIN CONFIGURATION TOP VIEW TOP VIEW BD 10 RT 1 BD 1 10 RT BOOST 2 9 V C BOOST 2 9 V C SW 3 11 8 FB 11 SW 3 8 FB V 4 7 PG IN V 4 7 PG IN RUN/SS 5 6 SYNC RUN/SS 5 6 SYNC MSE PACKAGE 10-LEAD PLASTIC MSOP DD PACKAGE = 45C/W, = 10C/W JA JC 10-LEAD (3mm 3mm) PLASTIC DFN EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB = 45C/W, = 10C/W JA JC EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3480EDD PBF LT3480EDD TRPBF LCTP 10-Lead (3mm 3mm) Plastic DFN 40C to 125C LT3480IDD PBF LT3480IDD TRPBF LCTP 40C to 125C 10-Lead (3mm 3mm) Plastic DFN LT3480EMSE PBF LT3480EMSE TRPBF LTCTM 10-Lead Plastic MSOP 40C to 125C LT3480IMSE PBF LT3480IMSE TRPBF LTCTM 10-Lead Plastic MSOP 40C to 125C LT3480HMSE PBF LT3480HMSE TRPBF LTCTM 10-Lead Plastic MSOP 40C to 150C LT3480MPMSE PBF LT3480MPMSE TRPBF LTCTM 10-Lead Plastic MSOP 55C to 150C LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3480EDD LT3480EDD TR LCTP 40C to 125C 10-Lead (3mm 3mm) Plastic DFN LT3480IDD LT3480IDD TR LCTP 10-Lead (3mm 3mm) Plastic DFN 40C to 125C LT3480EMSE LT3480EMSE TR LTCTM 10-Lead Plastic MSOP 40C to 125C LT3480IMSE LT3480IMSE TR LTCTM 10-Lead Plastic MSOP 40C to 125C LT3480HMSE LT3480HMSE TR LTCTM 10-Lead Plastic MSOP 40C to 150C LT3480MPMSE LT3480MPMSE TR LTCTM 10-Lead Plastic MSOP 55C to 150C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. For more information on lead free part marking, go to: