POWER LOSS (W) LTC3613 24V, 15A Monolithic Step Down Regulator with Differential Output Sensing FEATURES DESCRIPTION n Wide V Range: 4.5V to 24V The LTC 3613 is a monolithic synchronous step-down IN V Range: 0.6V to 5.5V at up to 15A switching regulator capable of regulating outputs from 0.6V OUT n 0.67% Output Voltage Accuracy to 5.5V with up to 15A output current. The controlled on-time n Controlled On-Time Valley Current Mode Architecture, constant frequency valley current mode architecture allows for Excellent Current Sharing Capability both fast transient response and constant frequency switch- n Frequency Programmable from 200kHz to 1MHz ing in steady-state operation, independent of V , V and IN OUT and Synchronizable to External Clock load. This also provides excellent current sharing capability. n R or Inductor DCR Current Sensing With SENSE Differential output voltage sensing along with a precision Accurate Current Limit internal reference combine to offer 0.67% output regula- n Fast Transient Response tion, even if the output ground reference deviates from n Differential Output Voltage Sensing Allowing 500mV local ground by 500mV. The switching frequency can be Common Mode Remote Ground programmed from 200kHz to 1MHz with an external resis- n t = 65ns t = 105ns ON(MIN) OFF(MIN) tor. The switching frequency is also phase synchronizable n Overvoltage Protection and Current Limit Foldback to an external clock in applications where switching noise/ n Power Good Output Voltage Monitor EMI reduction is crucial. n Voltage Tracking Start-Up n Very low t and t times allow for near 0% and near 100% External V Input for Bypassing Internal LDO ON OFF CC n duty cycles, respectively. Voltage tracking soft start-up is Micropower Shutdown: I = 15A Q n provided for tracking and sequencing applications. Safety fea- 7mm 9mm 56-pin QFN Package tures include output overvoltage protection, programmable APPLICATIONS current limit with foldback, and power good monitoring. L, LT, LTC, LTM, OPTI-LOOP, Linear Technology and the Linear logo are registered trademarks n Distributed Power System and Hot Swap and No R is a trademark of Linear Technology Corporation. All other SENSE n trademarks are the property of their respective owners. Protected by U.S. Patents including Point-of-Load Converters 5481178, 5487554, 6580258, 6304066, 6476589, 6774611. n Servers TYPICAL APPLICATION Efficiency and Power Loss High Efficiency High Power Step-Down Converter vs Load Current INTV CC PV 100 3.5 IN V IN SV IN PULSE-SKIPPING MODE 4.5V TO 24V + 90 3.0 0.1F 82F 80 LTC3613 100k PGOOD V OUT 2.5 70 10 SENSE 60 2.0 RUN 1000pF 10 FORCED + 50 SENSE CONTINUOUS V RNG 0.47H 1.5m V OUT MODE 1.5 40 MODE/PLLIN SW 1.5V 0.1F 0.1F 15A EXTV 30 CC 15k 1.0 TRACK/SS BOOST 20 47pF 0.5 V = 12V IN 10 10k V = 1.5V INTV OUT CC 0 0 270pF + 4.7F 330F 0.01 0.1 1 10 21k PGND 2 ITH LOAD CURRENT (A) 115k 3613 TA01a + RT V OSNS SGND V OSNS 3613 TA01 3613fa 1 EFFICIENCY (%)LTC3613 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW Supply Voltage (PV , SV ) ....................... 0.3V to 24V IN IN Boost Voltage ............................................ 0.3V to 30V SW Voltage ................................................ 0.3V to 24V PV 1 44 PGND INTV , EXTV , (BOOST-SW), MODE /PLLIN, IN CC CC PV 2 43 PGND IN V , PGOOD, RUN Voltages ....................... 0.3V to 6V RNG PV 3 42 PGND IN + PV 4 41 PGND IN V , V Voltages ........ 0.6V to (INTV + 0.3V) PV SW OSNS OSNS CC IN PV 5 40 PGND IN +, 57 58 V , SENSE SENSE Voltages ................. 0.6V to 6V OUT PV 6 39 PGND IN PV 7 38 PGND IN RT, ITH Voltages ..................... 0.3V to (INTV + 0.3V) CC PV 8 37 PGND IN TRACK/SS Voltages ..................................... 0.3V to 5V PV 9 36 PGND IN SW 10 35 SW Operating Junction Temperature Range BOOST 11 34 INTV CC (Notes 2, 4) ............................................ 40C to 125C SGND 12 33 INTV CC PGOOD 13 32 SV IN SGND Storage Temperature Range .................. 65C to 150C + SNS 14 31 MODE/PLLIN 59 SNS 15 30 EXTV CC SGND 16 29 SGND WKH PACKAGE 56-LEAD (7mm 9mm) MULTIPAD QFN T = 125C, = 29C/W JMAX JA ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3613EWKH PBF LTC3613EWKH TRPBF LTC3613WKH 56-Lead (7mm 9mm) Plastic QFN 40C to 125C LTC3613IWKH PBF LTC3613IWKH TRPBF LTC3613WKH 56-Lead (7mm 9mm) Plastic QFN 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. For more information on lead free part marking, go to: