Datasheet LT8708-1 (Analog Devices) - 3

LT8708-1
ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1)
VCSP – VCSN, VCSPIN – VCSNIN, VCSPOUT – VCSNOUT ... –0.3V to 0.3V CSP, CSN Voltage ... –0.3V to 3V TOP VIEW VC Voltage (Note 2) ... –0.3V to 2.2V V CC RT, FBOUT, SS Voltage .. –0.3V to 5V LDO33 IMON_ON IMON_OP MODE SWEN INT V INCHIP IMON_INP, IMON_INN, IMON_OP, 40 39 38 37 36 35 34 CLKOUT 1 33 CSPIN IMON_ON, ICP, ICN Voltage ... –0.3V to 5V SS 2 32 CSNIN SYNC Voltage .. –0.3V to 5.5V SHDN 3 INTV 31 CSNOUT CC, GATEVCC Voltage .. –0.3V to 7V CSN 4 30 CSPOUT VBOOST1 – VSW1, VBOOST2 – VSW2 .. –0.3V to 7V CSP 5 SWEN, RVSOFF Voltage ... –0.3V to 7V ICN 6 29 EXTVCC SWEN Current ...0.5mA DIR 7 41 GND 28 ICP RVSOFF Current ...1mA FBIN 8 27 VINHIMON FBOUT 9 FBIN, SHDN Voltage .. –0.3V to 30V 26 VOUTLOMON VC 10 VINHIMON Voltage ... –0.3V to 30V 25 RVSOFF IMON_INP 11 VOUTLOMON Voltage .. –0.3V to 5V IMON_INN 12 24 BOOST1 DIR, MODE Voltage .. –0.3V to 5V RT 13 23 TG1 CSNIN, CSPIN, CSPOUT, CSNOUT Voltage ...–0.3V to 80V SYNC 14 22 SW1 V 15 16 17 18 19 20 21 INCHIP, EXTVCC Voltage .. –0.3V to 80V SW1, SW2 Voltage ...81V (Note 6) CC GND BG1 BG2 TG2 TEV SW2 BOOST1, BOOST2 Voltage ... –0.3V to 87V GA BOOST2 BG1, BG2, TG1, TG2 ...(Note 5) UHG PACKAGE 40-LEAD (5mm × 8mm) PLASTIC QFN LDO33, CLKOUT .. (Note 8) TJMAX = 150°C, θJA = 36°C/W, θJC = 38°C/W Operating Junction Temperature Range EXPOSED PAD (PIN 41) IS GND, MUST BE SOLDERED TO PCB LT8708-1E (Notes 3, 8) ...–40°C to 125°C LT8708-1I (Notes 3, 8) ..–40°C to 125°C LT8708-1H (Notes 3, 8) ...–40°C to 150°C Storage Temperature Range ...–65°C to 150°C
ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT8708EUHG-1#PBF LT8708EUHG-1#TRPBF 87081 40-Lead (5mm × 8mm) Plastic QFN –40°C to 125°C LT8708IUHG-1#PBF LT8708IUHG-1#TRPBF 87081 40-Lead (5mm × 8mm) Plastic QFN –40°C to 125°C LT8708HUHG-1#PBF LT8708HUHG-1#TRPBF 87081 40-Lead (5mm × 8mm) Plastic QFN –40°C to 150°C Consult ADI Marketing 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. Rev 0 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 Block Diagram Operation Applications Information Package Description Typical Application Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Common LT8708-1 and LT8708 Features Adding Phases to an LT8708 Application Adding Phases: The Master LT8708 Adding Phases: The Slave LT8708-1 Start-Up Start-Up: SWEN Pin Start-Up: Soft-Start of Switching Regulator Control Overview Power Switch Control Unidirectional and Bidirectional Conduction Error Amplifiers Transfer Function: IOUT(SLAVE) Vs IOUT(MASTER) Transfer Function: CCM Transfer Function: DCM, HCM and Burst Mode Operation Current Monitoring and Limiting Monitoring: IOUT(SLAVE) Monitoring and Limiting: IIN(SLAVE) Multiphase Clocking Applications Information Quick-Start Multiphase Setup Quick Setup: Design the Master Phase Quick Setup: Design the Slave Phase(s) Quick Setup: Evaluation Choosing the Total Number of Phases Operating Frequency Selection CIN and COUT Selection CIN and COUT Selection: VIN Capacitance CIN and COUT Selection: VOUT Capacitance VINHIMON, VOUTLOMON and RVSOFF Configuring the IIN(SLAVE) Current Limits Regulating IOUT(SLAVE) IOUT(SLAVE): Circuit Description IOUT(SLAVE): Configuration Loop Compensation Voltage Lockouts Circuit Board Layout Checklist Design Example Typical Applications Package Description Typical Application Related Parts