LT8603 42V, Low I , Quad Output Triple Monolithic Q Buck Converter and Boost Controller FEATURES DESCRIPTION n Flexible Power Supply System Capable of Four The LT 8603 is a highly flexible, quad output regulator Regulated Outputs with V << V combining two high input voltage capable monolithic BATT OUT n Two High Voltage Synchronous Buck Regulators step-down switching regulators, one low input voltage n 3V to 42V Input Voltage Range capable monolithic step-down regulator, and a boost n Output Currents Up to 2.5A and 1.5A controller to satisfy a wide range of applications while n One Low Voltage Synchronous Buck Regulator occupying minimal board space. n 2.6V to 5.5V Input Voltage Range With the boost controller configured to supply the chip n Output Currents Up to 1.8A V supply, the LT8603 produces three precisely regulated IN n One Boost Controller Allows Buck Converters to outputs even when the boost input voltage falls signifi- Regulate with V << V BATT OUT cantly below the regulated output voltages, such as dur- n Selectable Burst Mode Operation Allows Low ing an automotive cold crank scenario. Alternatively, with 28A I with High Voltage Channels Active Q the boost controller driven from one of the step-down n Programmable Power-On Reset regulator outputs or configured as a SEPIC, the LT8603 n Individual Channel Power Good Indicators provides four precisely regulated outputs over a wide n Step-Down Switching Frequency: 250kHz to 2.2MHz input voltagerange. n Available in 40-Lead QFN (6mm 6mm) Package n The LT8603 provides robust regulation by including a AEC-Q100 Qualified for Automotive Applications cycle-by-cycle current limit for all step-down regulators, thermal shutdown, and a boost controller that can tolerate APPLICATIONS reverse battery connections and negative transient input n Automotive Stop-Start and ColdCrank Ride Through voltages down to 42V. n Last-Gasp CPU Power Hold-Up All registered trademarks and trademarks are the property of their respective owners. n Industrial Controls and Power Supplies TYPICAL APPLICATION Cold Crank Tolerant Automotive Triple Output Supply LT8603 Response to a Cold Crank Automotive Input Waveform V OUT4 BATT 2V TO 42V 8V FOR (BOOST 2V < V < 8.5V BATT START-UP EN/UVLO V PV PV ISP4 ISN4 IN IN1 IN2 ABOVE 4.3V) V BATT GATE4 INTV CC4 V OUT4 INTV CC FB4 FSEL4A FSEL4B BST1 RT SW1 OUT1 SYNC VOLTAGE 5V, 1.5A CPOR 2V/DIV 2 V LT8603 FB1 OUT1 TRKSS1-2 BST2 V OUT2 PV OUT2 IN3 SW2 3.3V, RUN3 2.5A I V PVIN3 OUT3 OUT2 BIAS FB2 4 0V PG1-4 PG1-4 SW3 OUT3 1.2V, 1.8A POREN POREN 8603 TA01b TIME (10ms/DIV) RESET RST GND FB3 8603 TA01a Rev. B 1 Document Feedback For more information www.analog.comLT8603 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW Supply Voltages V , PV ............................................ 0.3V to 42V IN IN1,2 PV ....................................................... 0.3V to 6V IN3 40 39 38 37 36 35 34 33 32 31 EN/UVLO .................................................................. 42V PG1 1 30 RUN3 GND 2 29 ISP4, ISN4 .................................................. 42V to 42V RT SW1 3 28 INTV CC TRKSS1-2, RUN3, FB4, PG1-4, SYNC .........................6V BST1 4 27 FB3 FSEL4A, FSEL4B, RST .................................................6V BST2 5 26 FB1 41 FB1-3, CPOR, POREN ...............................................3.6V GND SW2 6 25 FB2 BIAS ........................................................... 0.3V to 15V SW2 7 24 FB4 Operating Junction Temperature (Notes 2, 5) GND 8 23 V IN LT8603E ............................................ 40C to 125C BIAS 9 22 EN/UVLO PG2 10 21 TRKSS1 LT8603I ............................................. 40C to 125C 11 12 13 14 15 16 17 18 19 20 LT8603J ............................................ 40C to 150C Storage Temperature Range .................. 65C to 150C UJ PACKAGE 40-LEAD (6mm 6mm) PLASTIC QFN = 33C/W, = 2C/W JA JC EXPOSED PAD (PIN 41) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT8603EUJ PBF LT8603EUJ TRPBF LT8603UJ 40-Lead (6mm 6mm) Plastic QFN 40C to 125C LT8603IUJ PBF LT8603IUJ TRPBF LT8603UJ 40-Lead (6mm 6mm) Plastic QFN 40C to 125C LT8603JUJ PBF LT8603JUJ TRPBF LT8603UJ 40-Lead (6mm x 6mm) Plastic QFN 40C to 150C AUTOMOTIVE PRODUCTS** LT8603EUJ WPBF LT8603EUJ WTRPBF LT8603UJ 40-Lead (6mm 6mm) Plastic QFN 40C to 125C LT8603IUJ WPBF LT8603IUJ WTRPBF LT8603UJ 40-Lead (6mm 6mm) Plastic QFN 40C to 125C LT8603JUJ WPBF LT8603JUJ WTRPBF LT8603UJ 40-Lead (6mm 6mm) Plastic QFN 40C to 150C 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. **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 thesemodels. Rev. B 2 For more information www.analog.com PG4 PG3 FSEL4A POREN GND GND PV PV IN2 IN1 GATE4 SW3 INTV GND CC4 FSEL4B PV IN3 ISN4 SYNC ISP4 RST TRKSS2 CPOR