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Numéro de sérieLTC3853
CategoriePower Management => DC-DC Converters => Step-up
DescriptionTriple Output, Multiphase Synchronous Step-Down Controller
The LTC®3853 is a high performance triple output stepdown switching regulator controller that drives all N-channel synchronous power MOSFET stages. Power loss and supply noise are minimized by operating the output stages out of phase. The part can be configured as a dual phase controller plus a single phase controller if needed. The part can also be configured to provide a single 3-phase output for even higher output currents.
SociétéLinear Technology Corporation
DatasheetTélécharger LTC3853 datasheet
 
 
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    LTC3853 Triple Output, Multiphase Synchronous Step-Down Controller DESCRIPTION

    The is a high performance triple output stepdown switching regulator controller that drives all N-channel synchronous power MOSFET stages. Power loss and supply noise are minimized by operating the output stages out of phase. The part can be configured as a dual phase controller plus a single phase controller if needed. The part can also be configured to provide a single 3-phase output for even higher output currents. A wide 24V (28V maximum) input voltage supply range encompasses most battery chemistries and intermediate bus voltages. Phase 3 can regulate output voltages 13.5V. A constant frequency current mode architecture allows for a phase-lockable frequency to 750kHz. Independent TK/SS pins for each output ramps the output voltages and can be configured for coincident or ratiometric tracking. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The MODE/PLLIN pin selects among Burst Mode® operation, pulse-skipping or continuous inductor current modes.

    Triple, 120° Phased Controllers Reduce Required Input Capacitance and Power Supply Induced Noise Configurable a 180° Dual Phase Controller Plus a Single Phase Controller The Third Phase Can Regulate a 13.5V Output High Efficiency: to 92% RSENSE or DCR Current Sensing ±0.75% 0.8V Output Voltage Accuracy Phase-Lockable Fixed Frequency to 750kHz Supports Pre-Biased Outputs Dual N-Channel MOSFET Synchronous Drive Wide VIN Range: to 24V Operation (28V Abs Max) Adjustable Soft-Start Current Ramping or Tracking Foldback Output Current Limiting Output Overvoltage Protection Dual Power Good Output Voltage Monitors × 6mm QFN Package

    L, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including

    Input Supply Voltage (VIN)......................... to ­0.3V Topside Driver Voltages to ­0.3V Switch Voltage to ­5V INTVCC, PGOOD3, DRVCC12, EXTVCC, SENSE1­, SENSE2­ Voltages..................................... VFB2........................................................ 300A Max IFB2 MODE/PLLIN, TK/SS2, TK/SS3 Voltages..................... INTVCC VFB1, VFB3 Voltages...... INTVCC to ­0.3V INTVCC Peak Output Current................................150mA Operating Temperature Range (Note to 125°C Junction Temperature (Note 3)............................. 125°C Storage Temperature Range................... to 125°C

    UJ PACKAGE × 6mm) PLASTIC QFN TJMAX = 33°C/W EXPOSED PAD (PIN 41) IS PGND, MUST BE SOLDERED TO PCB

    LEAD FREE FINISH LTC3853EUJ#PBF LTC3853IUJ#PBF LEAD BASED FINISH LTC3853EUJ LTC3853IUJ TAPE AND REEL LTC3853EUJ#TRPBF LTC3853IUJ#TRPBF TAPE AND REEL LTC3853EUJ#TR LTC3853IUJ#TR PART MARKING* LTC3853 PART MARKING* LTC3853 PACKAGE DESCRIPTION × 6mm) Plastic QFN × 6mm) Plastic QFN PACKAGE DESCRIPTION × 6mm) Plastic QFN × 6mm) Plastic QFN TEMPERATURE RANGE to 125°C TEMPERATURE RANGE 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/

    SYMBOL VFB1,2,3 IFB1,2,3 VREFLNREG VLOADREG PARAMETER Regulated Feedback Voltage Feedback Current Reference Voltage Line Regulation Output Voltage Load Regulation Main Control Loops ITH1,2,3 Voltage = 1.2V (Note 4) ITH1,2,3 Voltage to 85°C) (Note 4) (Note 4) VIN to 24V (Note 4) (Note 4) Measured in Servo Loop; ITH Voltage to 0.7V Measured in Servo Loop; ITH Voltage gm1,2,3 IQ Transconductance Amplifier gm Input DC Supply Current Normal Mode Shutdown Undervoltage Lockout on INTVCC UVLO Hysteresis Feedback Overvoltage Lockout Sense Pin Current Soft-Start Charge Current RUN Pin ON Threshold RUN Pin Hysteresis Maximum Current Sense Threshold = 3.3V, ILIM = 3.3V, ILIM = Float = 3.3V, ILIM = INTVCC In Dropout TG High TG Low BG High BG Low (Note 6) CLOAD = 3300pF CLOAD = 3300pF (Note 6) CLOAD = 3300pF CLOAD = 3300pF (Note 6) CLOAD = 3300pF Each Driver (Note 6) CLOAD = 3300pF Each Driver (Note 7)

    The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are = 25°C, VIN = 5V, unless otherwise noted.

    = 1.2V, Sink/Source 5A (Note 4) (Note 5) VIN = 0V VINTVCC Ramping Down Measured at VFB1,2,3 VSENSE VRUN2, VRUN3 Rising

    DFMAX TG RUP TG RDOWN BG RUP BG RDOWN BG1,2,3 tf TG/BG t1D BG/TG t2D tON(MIN)

    Maximum Duty Factor TG Driver Pull-Up On-Resistance TG Driver Pull-Down On-Resistance BG Driver Pull-Up On-Resistance BG Driver Pull-Down On-Resistance TG Transition Time: Rise Time Fall Time BG Transition Time: Rise Time Fall Time Top Gate Off to Bottom Gate On Delay Synchronous Switch-On Delay Time Bottom Gate Off to Top Gate On Delay Top Switch-On Delay Time Minimum On-Time