POWER LOSS (mW) LTC3611 10A, 32V Monolithic Synchronous Step-Down DC/DC Converter Fe Aserut Dnoitpircse n 10A Output Current The LTC 3611 is a high efciency, monolithic synchronous n Wide V Range = 4.5V to 32V (36V Maximum) step-down DC/DC converter that can deliver up to 10A IN n Internal N-Channel MOSFETs output current from a 4.5V to 32V (36V maximum) input n True Current Mode Control supply. It uses a constant on-time valley current mode n Optimized for High Step-Down Ratios control architecture to deliver very low duty cycle opera- n t 100ns tion at high frequency with excellent transient response. 0N(MIN) n Extremely Fast Transient Response The operating frequency is selected by an external resistor n Stable with Ceramic C and is compensated for variations in V and V . OUT IN OUT n 1% 0.6V Voltage Reference The LTC3611 can be congured for discontinuous or n Power Good Output Voltage Monitor forced continuous operation at light load. Forced continu- n Adjustable On-Time/Switching Frequency (>1MHz) ous operation reduces noise and RF interference while n Adjustable Current Limit discontinuous mode provides high efciency by reducing n Programmable Soft-Start switching losses at light loads. n Output Overvoltage Protection n Fault protection is provided by internal foldback current Optional Short-Circuit Shutdown Timer n limiting, an output overvoltage comparator and an optional Low Shutdown I : 15A Q n short-circuit shutdown timer. Soft-start capability for sup- Available in a 9mm 9mm 64-Pin QFN Package ply sequencing is accomplished using an external timing Acilpp Asnoit capacitor. The regulator current limit is user programmable. A power good output voltage monitor indicates when n Point of Load Regulation the output is in regulation. The LTC3611 is available in a n Distributed Power Systems compact 9mm 9mm QFN package. 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. Patents including 5481178, 6100678, 6580258, 5847554, 6304066. t cipy A l Acilpp Anoit High Efciency Step-Down Converter Efciency and Power Loss vs Load Current 182k V OUT V I 0.1F ON ON 100 10000 V = 2.5V OUT V IN RUN/SS V 90 IN 4.5V TO 32V 10F V = 5V 80 IN 100pF 3 LTC3611 1000 V = 25V IN 70 1H V OUT 2.5V SW 60 680pF 10A 0.22F 100F 50 100 I BOOST 2 TH POWER LOSS, 12.5k 40 V = 5V IN 30 SGND INTV CC 30.1k 10 FCB 20 POWER LOSS, 39.2k V = 25V IN 4.7F 10 V INTV CC RNG PGND 1 0 PGOOD 0.01 0.1 1 10 11k EXTV V CC FB LOAD CURRENT (A) 3611 TA01b 9.5k 3611 TA01a 3611fd EFFICIENCY (%)LTC3611 A etulosbM Aix Mu M Ar sgnit p ni c no Frugi Anoit (Note 1) TOP VIEW Input Supply Voltage (V , I ) .................. 36V to 0.3V IN ON Boosted Topside Driver Supply Voltage (BOOST) ................................................ 42V to 0.3V SW Voltage ............................................ 36V to 0.3V PGND 1 48 SGND 65 INTV , EXTV , (BOOST SW), RUN/SS, PGND 2 47 SGND CC CC PGND PGND 3 46 SGND PGOOD Voltages .......................................... 7V to 0.3V SW 4 45 SGND FCB, V , V Voltages ............ INTV + 0.3V to 0.3V ON RNG CC SW 5 44 EXTV CC I , V Voltages ....................................... 2.7V to 0.3V SW 6 43 V FB TH FB SW 7 42 SGND 66 Operating Junction Temperature Range SW 8 SW 41 I ON (Notes 2, 4) ............................................ 40C to 125C SW 9 40 SGND SW 10 39 FCB Storage Temperature Range ...................55C to 125C 68 SW 11 38 I TH SGND PV 12 37 V IN RNG PV 13 36 PGOOD IN 67 PV 14 35 V IN ON PV IN PV 15 34 SGND IN PV 16 33 SGND IN WP PACKAGE 64-LEAD (9mm 9mm) QFN MULTIPAD T = 125C, = 28C/W JMAX JA ro D re ni Fro MAnoit LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3611EWP PBF LTC3611EWP TRPBF LTC3611WP 40C to 125C 64-Lead (9mm 9mm) Plastic QFN LTC3611IWP PBF LTC3611IWP TRPBF LTC3611WP 64-Lead (9mm 9mm) Plastic QFN 40C to 125C LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3611EWP LTC3611EWP TR LTC3611WP 40C to 125C 64-Lead (9mm 9mm) Plastic QFN LTC3611IWP LTC3611IWP TR LTC3611WP 40C to 125C 64-Lead (9mm 9mm) Plastic QFN Consult LTC Marketing for parts specied with wider operating temperature ranges. *The temperature grade is identied by a label on the shipping container. For more information on lead free part marking, go to: