POWER LOSS (mW) LT3581 3.3A Boost/Inverting DC/DC Converter with Fault Protection FEATURES DESCRIPTION n 3.3A, 42V Combined Power Switch The LT 3581 is a PWM DC/DC converter with built-in fault n Master/Slave (1.9A/1.4A) Switch Design protection features to aid in protecting against output n Output Short Circuit Protection shorts, input/output overvoltages, and overtemperature n Wide Input Range: 2.5V to 22V Operating, conditions. The part consists of a 42V master switch, and 40V Maximum Transient a 42V slave switch that can be tied together for a total n Switching Frequency Up to 2.5MHz current limit of 3.3A. n Easily Configurable as a Boost, SEPIC, Inverting or The LT3581 is ideal for many local power supply designs. It Flyback Converter can be easily configured in Boost, SEPIC, Inverting or Flyback n User Configurable Undervoltage Lockout configurations, and is capable of generating 12V at 830mA, n Low V Switch: 250mV at 2.75A (Typical) CESAT or 12V at 625mA from a 5V input. In addition, the LT3581s n Can be Synchronized to External Clock slave switch allows the part to be configured in high voltage, n Can Be Synchronized to other Switching Regulators high power charge pump topologies that are very efficient n High Gain SHDN Pin Accepts Slowly Varying Input and require fewer components than traditional circuits. Signals n The LT3581s switching frequency range can be set bet ween 14-Pin 4mm 3mm DFN and 16-Lead MSE Packages 200kHz and 2.5MHz. The part may be clocked internally at a frequency set by the resistor from the RT pin to ground, or it may be synchronized to an external clock. A buffered APPLICATIONS version of the clock signal is driven out of the CLKOUT n Local Power Supply pin, and may be used to synchronize other compatible n Vacuum Fluorescent Display (VFD) Bias Supplies switching regulator ICs to the LT3581. n TFT-LCD Bias Supplies The LT3581 also features innovative SHDN pin circuitry that n Automotive Engine Control Unit (ECU) Power allows for slowly varying input signals and an adjustable L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. undervoltage lockout function. Additional features such Protected by U.S. Patents, including 7579816. as frequency foldback and soft-start are integrated. The LT3581 is available in 14-Pin 4mm 3mm DFN and 16- Lead MSE packages. Efficiency and Power Loss vs TYPICAL APPLICATION Load Current 100 2000 Output Short Protected, 5V to 12V Boost Converter Operating at 2MHz 95 1800 1.5H V OUT V IN 90 1600 12V 5V 830mA 85 1400 4.7F 6.04k SW1 SW2 80 1200 18.7k V FB IN 75 1000 100k 130k FAULT GATE V IN 70 800 4.7F SHDN CLKOUT 65 600 RT V LT3581 C 4.7F 10k 56pF 60 400 SYNC SS 10.5k 43.2k 55 200 GND 0.1F 1nF 50 0 3581 TA01 0 200 400 600 800 1000 LOAD CURRENT (mA) 3581 TA01b 3581fb 1 For more information www.linear.com/LT3581 EFFICIENCY (%)LT3581 ABSOLUTE MAXIMUM RATINGS (Note 1) V Voltage ................................................. 0.3V to 40V FAULT Current .....................................................500A IN SW1/SW2 Voltage ..................................... 0.4V to 42V CLKOUT Voltage .......................................... 0.3V to 3V RT Voltage ................................................... 0.3V to 5V CLKOUT Current.......................................................1mA SS, FB Voltage .......................................... 0.3V to 2.5V Operating Junction Temperature Range V Voltage .................................................... 0.3V to 2V LT3581E (Notes 2, 4) ......................... 40C to 125C C SHDN Voltage ............................................ 0.3V to 40V LT3581I (Notes 2, 4) .......................... 40C to 125C SYNC Voltage ............................................ 0.3V to 5.5V LT3581H (Notes 2, 4) .........................40C to 150C GATE Voltage ............................................. 0.3V to 80V Storage Temperature Range ..................65C to 150C FAULT Voltage ............................................ 0.3V to 40V PIN CONFIGURATION TOP VIEW TOP VIEW FB 1 14 SYNC FB 1 16 SYNC V 2 13 SS C 2 V 15 SS C GATE 3 12 RT GATE 3 14 RT 15 4 FAULT 17 13 SHDN FAULT 4 11 SHDN GND V 5 GND 12 CLKOUT IN V 5 10 CLKOUT 6 SW1 11 SW2 IN SW1 7 10 SW2 SW1 6 9 SW2 8 SW1 9 SW2 SW1 7 8 SW2 MSE PACKAGE 16-LEAD PLASTIC MSOP DE14 PACKAGE T = 125C, = 45C/W, = 10C/W JMAX JA JC 14-PIN (4mm 3mm) PLASTIC DFN EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB T = 125C, = 43C/W, = 4.3C/W JMAX JA JC EXPOSED PAD (PIN 15) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3581EDE PBF LT3581EDE TRPBF 3581 14-Lead (4mm 3mm) Plastic DFN 40C to 125C LT3581IDE PBF LT3581IDE TRPBF 3581 40C to 125C 14-Lead (4mm 3mm) Plastic DFN LT3581HDE PBF LT3581HDE TRPBF 3581 14-Lead (4mm 3mm) Plastic DFN 40C to 150C LT3581EMSE PBF LT3581EMSE TRPBF 3581 16-Lead Plastic MSOP 40C to 125C LT3581IMSE PBF LT3581IMSE TRPBF 3581 16-Lead Plastic MSOP 40C to 125C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: