DatasheetsPDF.com

LTC3874-1 Dataheets PDF



Part Number LTC3874-1
Manufacturers Analog Devices
Logo Analog Devices
Description PolyPhase Step-Down Synchronous Slave Controller
Datasheet LTC3874-1 DatasheetLTC3874-1 Datasheet (PDF)

LTC3874-1 PolyPhase Step-Down Synchronous Slave Controller with Sub-Milliohm DCR Sensing Features n Phase Extender for High Phase Count Voltage Rails n Operates with Power Blocks, DrMOS or External Gate Drivers and MOSFETs n Accurate Phase-to-Phase Current Sharing n Sub-Milliohm DCR Current Sensing n Phase-Lockable Fixed Frequency 250kHz to 1MHz n Immediate Response to Master IC's Fault n Up to 12-Phase Operation n Wide VIN Range: 4.5 to 38V n VOUT Range : Up to 3.5V (LOWDCR Pin High) Up to 5.5.

  LTC3874-1   LTC3874-1



Document
LTC3874-1 PolyPhase Step-Down Synchronous Slave Controller with Sub-Milliohm DCR Sensing Features n Phase Extender for High Phase Count Voltage Rails n Operates with Power Blocks, DrMOS or External Gate Drivers and MOSFETs n Accurate Phase-to-Phase Current Sharing n Sub-Milliohm DCR Current Sensing n Phase-Lockable Fixed Frequency 250kHz to 1MHz n Immediate Response to Master IC's Fault n Up to 12-Phase Operation n Wide VIN Range: 4.5 to 38V n VOUT Range : Up to 3.5V (LOWDCR Pin High) Up to 5.5V (LOWDCR Pin Low) n Proprietary Current Mode Control Loop n Programmable CCM/DCM Operation n Programmable Phase Shift Control n 24-Lead (4mm × 4mm) QFN Package Applications n High Current Distributed Power Systems n Telecom, Datacom and Storage Systems n Intelligent Energy Efficient Power Regulation Description The LTC®3874-1 is a dual PolyPhase® current mode synchronous step-down slave controller. It enables high current, multiphase applications when paired with a companion master controller by extending the phase count. Compatible master controllers include the LTC3884-1, LTC3774, LTC3875, LTC3877 and LTC3866. The LTC3874-1 employs a unique architecture that enhances the signal-to-noise ratio of the current sense signal, allowing the use of submilliohm DC resistance power inductors to maximize efficiency while reducing switching jitter. Its peak current mode architecture allows for accurate phase-to-phase current sharing even for dynamic loads. Effectively working with a master controller, the LTC3874-1 supports all the programmable features as well as fault protection. L, LT, LTC, LTM, Linear Technology, the Linear logo, PolyPhase and µModule are registered trademarks of Analog Devices, Inc. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 5705919, 5929620, 6144194, 6177787, 6580258, 5408150. Typical Application VIN 7V TO 14V High Efficiency, 4-Phase 1.8V/120A Step-Down Supply 470µF + ×2 (0.29mΩ DCR) 0.215µH 100µF ×3 649Ω 0.22µF DrMOS LTC3884-1 1.8V VSENSE0+ VSENSE1+ RUN0 RUN1 FAULT0 FAULT1 PGOOD0 PGOOD1 ITH0 ITH1 SYNC VIN LTC3874-1 PWM0 PWM1 DrMOS ISENSE0+ ISENSE0– ISENSE1+ ISENSE1– RUN0 RUN1 FAULT0 FAULT1 MODE0 MODE1 ITH0 ITH1 SYNC INTVCC VCC0 VCC1 PHASMD LDWDCR ILIM FREQ GND 100k 4.7µF (0.29mΩ DCR) 0.215µH 649Ω 0.22µF 100µF ×3 REFER TO LTC3884-1 DATA SHEET FOR MASTER SETUP PIN NOT USED IN THIS CIRCUIT: EXTVCC 38741 TA01a For more information www.linear/LTC3874-1 + VOUT 1.8V 120A 470µF ×2 EFFICIENCY (%) POWER LOSS (W) 4-Phase Efficiency and Power Loss vs Output Current, SubMilliohm DCR vs Traditional DCR 100 20 VIN = 12V VOUT = 1.8V 95 fSW = 425kHz 17 CCM 90 EFFICIENCY 14 85 11 80 POWER LOSS 8 0.29mΩ 75 1.5mΩ 5 0.29mΩ 1.5mΩ 70 2 0 10 20 30 40 50 60 70 80 90 100 110 120 LOAD CURRENT (A) 38741 TA01b 38741f 1 LTC3874-1 Absolute Maximum Ratings (Note 1) VIN.............................................................. −0.3V to 40V VCC0, VCC1..................................................... −0.3V to 6V ISENSE0+, ISENSE0–, ISENSE1+, ISENSE1–..... −0.3V to INTVCC EXTVCC, INTVCC, RUN0, RUN1..................... −0.3V to 6V MODE0, MODE1, ILIM, LOWDCR, PHASMD, FREQ..................................... −0.3V to INTVcc SYNC, FAULT0, FAULT1, ITH0, ITH1.......... −0.3V to INTVcc INTVCC Peak Output Current.................................100mA Operating Junction Temperature Range (Note 2)................................................... −40°C to 125°C Storage Temperature Range................... −65°C to 150°C Pin Configuration TOP VIEW MODE0 ITH0 LOWDCR FAULT0 FAULT1 PWM0 ISENSE0+ 1 ISENSE0– 2 RUN0 3 RUN1 4 ISENSE1– 5 ISENSE1+ 6 24 23 22 21 20 19 18 VCC0 17 VIN 25 16 INTVCC GND 15 EXTVCC 14 VCC1 13 PWM1 7 8 9 10 11 12 MODE1 ITH1 FREQ ILIM SYNC PHASMD UF PACKAGE 24-LEAD (4mm × 4mm) PLASTIC QFN TJMAX = 125°C, θJA = 46.9°C/W, θJC_BOT = 4.5°C/W EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB Order Information http://www.linear.com/product/LTC3874-1#orderinfo LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3874EUF-1#PBF LTC3874EUF-1#TRPBF 38741 24-Lead (4mm × 4mm) Plastic QFN –40°C to 125°C LTC3874IUF-1#PBF LTC3874IUF-1#TRPBF 38741 24-Lead (4mm × 4mm) Plastic QFN –40°C to 125°C 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: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix. 38741f 2 For more information www.linear.com/LTC3874-1 LTC3874-1 Electrical Characteristics The l denotes the specifications which apply o.


LTC3870-1 LTC3874-1 LTC3897-2


@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site.
(Privacy Policy & Contact)