POWER LOSS (W) LTC3604 2.5A, 15V Monolithic Synchronous Step-Down Regulator FEATURES DESCRIPTION n 3.6V to 15V Operating Input Voltage Range The LTC 3604 is a high efficiency, monolithic synchronous n 2.5A Output Current buck regulator using a phase-lockable controlled on-time, n Up to 95% Efficiency current mode architecture capable of supplying up to 2.5A n Very Low Duty Cycle Operation: 5% at 2.25MHz of output current. The operating supply voltage range is n Adjustable Switching Frequency: 800kHz to 4MHz from 3.6V to 15V, making it suitable for a wide range of n External Frequency Synchronization power supply applications. n Current Mode Operation for Excellent Line and Load The operating frequency is programmable from 800kHz to Transient Response 4MHz with an external resistor enabling the use of small n User Selectable Low Ripple (20mV Typical) P-P surface mount inductors. For switching noise sensitive Burst Mode (No Load I = 300A) or Forced Q applications, the LTC3604 can be externally synchronized Continuous Operation over the same frequency range. An internal phase-locked n 0.6V Reference Allows Low Output Voltages loop aligns the on-time of the top power MOSFET to the n Short-Circuit Protected internal or external clock. This unique constant frequency/ n Output Voltage Tracking Capability controlled on-time architecture is ideal for high step-down n Power Good Status Output ratio applications that demand high switching frequencies n Available in Small, Thermally-Enhanced, 16-Pin QFN and fast transient response. (3mm 3mm) and MSOP Packages The LTC3604 offers two operational modes: Burst Mode APPLICATIONS operation and forced continuous mode to allow the user to optimize output voltage ripple, noise, and light load n Distributed Power Systems efficiency for a given application. Maximum light load n Lithium-Ion Battery-Powered Instruments efficiency is achieved with the selection of Burst Mode n Point-of-Load Power Supplies operation while forced continuous mode provides minimum L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks output ripple and constant frequency operation. and Hot Swap is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 5847554, 6580258, 6304066, 6476589, 6774611. TYPICAL APPLICATION Efficiency and Power Loss vs Load Current 100 10 High Efficiency 2.5A Step-Down Regulator 90 V IN 80 V BOOST IN 1 3.6V TO 15V RUN 0.1F 70 22F 1H V OUT 60 PGOOD 3.3V SW TRACK/SS 2.5A V 50 0.1 ON 180k 22pF 47F LTC3604 40 INTV FB CC 30 ITH 2.2F 40k V = 5V 0.01 IN RT 20 V = 12V IN MODE/SYNC 3604 TA01a 10 f = 2MHz O SGND PGND Burst Mode OPERATION 0 0.001 0.001 0.01 0.1 1 10 LOAD CURRENT (A) 3604 TA01b 3604fa 1 For more information www.linear.com/LTC3604 EFFICIENCY (%)LTC3604 ABSOLUTE MAXIMUM RATINGS (Note 1) SW, RUN .......................................... 0.3V to V + 0.3V V ............................................................. 0.3V to 16V IN IN SW Source Current (DC) .............................................3A V Transient Voltage ................................................18V IN Peak SW Source Current..................... Internally Limited BOOST .....................................................0.3V to 18.6V Operating Junction Temperature Range BOOST-SW ................................................ 0.3V to 3.6V (Notes 2, 3, 5) ....................................... 40C to 125C INTV ...................................................... 0.3V to 3.6V CC Storage Temperature Range .................. 65C to 125C ITH, RT.......................................0.3V to INTV + 0.3V CC Lead Temperature (Soldering, 10 sec) MODE/SYNC, FB ........................0.3V to INTV + 0.3V CC MSOP ...............................................................300C TRACK/SS .................................0.3V to INTV + 0.3V CC PGOOD, V ............................................... 0.3V to 16V ON PIN CONFIGURATION TOP VIEW TOP VIEW 1 PGOOD 16 15 14 13 SW 16 SW 2 15 MODE/SYNC MODE/SYNC 1 12 ITH PGND 3 14 V IN PGND 4 17 13 V IN PGOOD 2 11 FB 17 BOOST 5 SGND 12 RUN PGND SW RT 6 3 10 INTV 11 TRACK/SS CC V 7 10 I ON TH SW 4 9 SGND RT 8 9 FB 5 6 7 8 MSE PACKAGE 16-LEAD PLASTIC MSOP T = 125C, = 38C/W JMAX JA EXPOSED PAD (PIN 17) IS SGND, MUST BE SOLDERED TO PCB UD PACKAGE 16-LEAD (3mm 3mm) PLASTIC QFN T = 125C, = 45C/W JMAX JA EXPOSED PAD (PIN 17) IS PGND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3604EUD PBF LTC3604EUD TRPBF LFPT 16-Lead (3mm 3mm) Plastic QFN 40C to 125C LTC3604IUD PBF LTC3604IUD TRPBF LFPT 16-Lead (3mm 3mm) Plastic QFN 40C to 125C LTC3604EMSE PBF LTC3604EMSE TRPBF 3604 16-Lead Plastic MSOP 40C to 125C LTC3604IMSE PBF LTC3604IMSE TRPBF 3604 16-Lead Plastic MSOP 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. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: