LT3791 60V 4-Switch Synchronous Buck-Boost LED Driver Controller Fea T Descrip T n 4-Switch Single Inductor Architecture Allows V The LT 3791 is a synchronous 4-switch buck-boost LED IN Above, Below or Equal to V driver controller. The controller can regulate LED current OUT n Synchronous Switching: Up to 98.5% Efficiency up to 52V of LED string with input voltages above, below, n Wide V Range: 4.7V to 60V or equal to the output voltage. The constant-frequency, IN n Wide V Range: 0V to 60V (52V LED) forced-continuous current mode architecture allows its OUT n 6% LED Current Accuracy: 0V V < 52V frequency to be adjusted or synchronized from 200kHz to LED n True Color PWM and Analog Dimming 700kHz. No top MOSFET refresh switching cycle is needed n LED and Input Current Regulation with Current in buck or boost operation. With 60V input, 60V output Monitor Outputs capability and seamless transitions between operating n No Top MOSFET Refresh in Buck or Boost regions, the LT3791 is ideal for LED driver applications in n V Disconnected From V During Shutdown automotive, industrial, and even battery-powered systems. OUT IN n Open or Shorted LED Fault Protection For new designs we recommend the LT8391: 60V syn- n Capable of 100W or Greater per IC chronous 4-switch, buck-boost LED controller due to its n 38-Lead TSSOP with Exposed Pad numerous performance improvements over the LT3791. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered and True Color PWM a T is a trademark of Analog Devices, Inc. All other trademarks are the property of their respective owners. n Automotive Head Lamps/Running Lamps n General Purpose Lighting Typical a T 98.5% Efficient 100W (33.3V 3A) Buck-Boost LED Driver V IN 2.2F 15V TO 58V 100V 0.003 5 V INTV IN CC 4.7F 1F BST2 50 Efficiency vs V IN IVINN 0.1F BST1 4.7F 100 470nF 50V 1M TG1 0.1F 499k IVINP 5 SWI 98 EN/UVLO BOOST 10H 34.2k BUCK OVLO BG1 15.8k INTV CC BUCK-BOOST LT3791 96 SNSP 200k 200k 3A, 100W 28k 0.004 0.033 SHORTLED LED POWER 94 OPENLED SNSN PGND PWM 92 BG2 IVINMON SW2 ISMON TG2 90 CLKOUT 10 20 30 40 50 60 FB V REF INPUT VOLTAGE (V) ISP CTRL 3791 TA01b ISN 0.1F PWMOUT SS SYNC V RT SGND C 10nF 22nF 86.6k 300kHz 3791 TA01a 3791fc 1 For more information www.linear.com/LT3791 EFFICIENCY (%) ion pplica ions pplica ion uresLT3791 a Te Maxi Mu M r a T p c F T (Note 1) TOP VIEW Supply Voltages CTRL 1 38 OVLO Input Supply (V ) .....................................................60V IN SS 2 37 FB SW1, SW2 ......................................................1V to 60V PWM 3 36 V C OPENLED, SHORTLED ...............................................15V OPENLED 4 35 RT EN/UVLO, IVINP, IVINN, ISP, ISN ..............................60V SHORTLED 5 34 SYNC INTV , (BST1-SW1), (BST2-SW2) .............................6V CC V 6 33 CLKOUT REF TEST2, SYNC, RT, CTRL, OVLO, PWM .......................6V ISMON 7 32 TEST2 IVINMON, ISMON, FB, SS, V , V ............................6V C REF IVINMON 8 31 PWMOUT IVINP-IVINN, ISP-ISN, SNSP-SNSN .......................0.5V EN/UVLO 9 30 SGND SNSP, SNSN ...........................................................0.3V 39 IVINP 10 29 TEST1 SGND Operating Junction Temperature (Notes 2, 3) IVINN 11 28 SNSN LT3791E/LT3791I ............................... 40C to 125C V 12 27 SNSP IN LT3791H ............................................ 40C to 150C INTV 13 26 ISN CC LT3791MP ......................................... 55C to 150C TG1 14 25 ISP BST1 15 24 TG2 Storage Temperature Range .................. 65C to 150C SW1 16 23 NC Lead Temperature (Soldering, 10 sec) ...................300C PGND 17 22 BST2 BG1 18 21 SW2 BG2 19 20 PGND FE PACKAGE 38-LEAD PLASTIC TSSOP T = 150C, = 28C/W JMAX JA EXPOSED PAD (PIN 39) IS SGND, MUST BE SOLDERED TO PCB