Datasheet LTC7818 (Analog Devices) - 3

LTC7818
ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1)
Bias Input Supply Voltage (VBIAS) .. –0.3V to 40V TOP VIEW BOOST1, BOOST2, BOOST3 ... –0.3V to 46V Switch Voltage (SW1, SW2, SW3) .. –5V to 40V – + RUN1, RUN2, RUN3 Voltages ... –0.3V to 40V FREQ SENSE1 SENSE1 V FB1 ITH1 TRACK/SS1 PLLIN/SPREAD PGOOD1 TG1 SW1 SENSE1+, SENSE1– Voltages .. –0.3V to 40V 40 39 38 37 36 35 34 33 32 31 SENSE2+, SENSE2– Voltages ... –0.3V to 40V MODE 1 30 BOOST1 SENSE3+, SENSE3– Voltages ... –0.3V to 40V SS3 2 29 BG1 EXTV SENSE3+ 3 28 SW3 CC Voltage ... –0.3V to 30V INTV SENSE3– 4 27 TG3 CC, (BOOST1 – SW1), VFB3 5 41 (BOOST2 – SW2), (BOOST3 – SW3) ... –0.3V to 6V 26 BOOST3 GND ITH3 6 25 BG3 TRACK/SS1, TRACK/SS2 Voltages .. –0.3V to 6V IMON3 7 24 VBIAS ITH1, ITH2, ITH3 Voltages.. –0.3V to 2V RUN1 8 23 EXTVCC VFB3 Voltage... –0.3V to 40V RUN2 9 22 INTVCC VFB1, VFB2, SS3, IMON3 Voltages .. –0.3V to 6V RUN3 10 21 BG2 VPRG3, MODE, PGOOD1 Voltages ... –0.3V to 6V 11 12 13 14 15 16 17 18 19 20 – + PLLIN/SPREAD, FREQ, OV3 Voltages .. –0.3V to 6V V FB2 ITH2 OV3 TG2 SW2 BG1, BG2, BG3, TG1, TG2, TG3 .. (Note 9) VPRG3 SENSE2 SENSE2 BOOST2 Operating Junction Temperature Range (Notes 2,8) TRACK/SS2 UJ PACKAGE LTC7818E, LTC7818I .. –40°C to 125°C 40-LEAD (6mm × 6mm) PLASTIC QFN LTC7818H, LTC7818J ... –40°C to 150°C TJMAX = 150°C, θJA = 33°C/W EXPOSED PAD (PIN 41) IS GND, MUST BE SOLDERED TO PCB Storage Temperature Range .. –65°C to 150°C
ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC7818EUJ#PBF LTC7818EUJ#TRPBF LTC7818 40-Lead (6mm × 6mm) Plastic QFN –40°C to 125°C LTC7818IUJ#PBF LTC7818IUJ#TRPBF LTC7818 40-Lead (6mm × 6mm) Plastic QFN –40°C to 125°C LTC7818JUJ#PBF LTC7818JUJ#TRPBF LTC7818 40-Lead (6mm × 6mm) Plastic QFN –40°C to 150°C LTC7818HUJ#PBF LTC7818HUJ#TRPBF LTC7818 40-Lead (6mm × 6mm) Plastic QFN –40°C to 150°C
AUTOMOTIVE PRODUCTS**
LTC7818EUJ#WPBF LTC7818EUJ#WTRPBF LTC7818 40-Lead (6mm × 6mm) Plastic QFN –40°C to 125°C LTC7818IUJ#WPBF LTC7818IUJ#WTRPBF LTC7818 40-Lead (6mm × 6mm) Plastic QFN –40°C to 125°C LTC7818JUJ#WPBF LTC7818JUJ#WTRPBF LTC7818 40-Lead (6mm × 6mm) Plastic QFN –40°C to 150°C LTC7818HUJ#WPBF LTC7818HUJ#WTRPBF LTC7818 40-Lead (6mm × 6mm) Plastic QFN –40°C to 150°C Contact the factory for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix.
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Versions of this part are available with controlled manufacturing to support the quality and reliability requirements of automotive applications. These models are designated with a #W suffix. Only the automotive grade products shown are available for use in automotive applications. Contact your local Analog Devices account representative for specific product ordering information and to obtain the specific Automotive Reliability reports for these models. Rev. A For more information www.analog.com 3 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Main Control Loop Power and Bias Supplies (VBIAS, EXTVCC, and INTVCC) Shutdown and Start-Up (RUN1, RUN2, RUN3 and TRACK/SS1, TRACK/SS2, SS3 Pins) Light Load Operation: Burst Mode Operation, Pulse-Skipping, or Forced Continuous Mode (MODE Pin) Frequency Selection, Spread Spectrum, and Phase-Locked Loop (FREQ and PLLIN/SPREAD Pins) Boost Controller Operation When VIN > VOUT Boost Controller at Low Input Voltage Buck Controller Output Overvoltage Protection Buck Foldback Current Channel 1 Power Good (PGOOD1) Boost Overvoltage Indicator (OV3) Applications Information Inductor Value Calculation Inductor Core Selection Current Sense Selection Low Value Resistor Current Sensing Inductor DCR Current Sensing Setting the Operating Frequency Selecting the Light-Load Operating Mode Power MOSFET Selection Boost CIN and COUT Selection Buck CIN and COUT Selection Setting the Buck Output Voltage Setting Boost Output Voltage (VPRG3 Pin) RUN Pins and Undervoltage Lockout Soft-Start and Tracking (TRACK/SS1, TRACK/SS2, SS3 Pins) Single Output Two-Phase Operation INTVCC Regulators Topside MOSFET Driver Supply (CB, DB) Minimum On-Time Considerations Boost Channel Current Monitor (IMON3) Fault Conditions: Buck Current Limit and Foldback Fault Conditions: Buck Overvoltage Protection (Crowbar) Fault Conditions: Overtemperature Protection Phase-Locked Loop and Frequency Synchronization Efficiency Considerations Checking Transient Response Buck Design Example PC Board Layout Checklist PC Board Layout Debugging Typical Applications Package Description Revision History Typical Application Related Parts