LT3579/LT3579-1 6A Boost/Inverting DC/DC Converter with Fault Protection FEATURESDESCRIPTION n 6A, 42V Combined Power Switch The LT®3579 is a PWM DC/DC converter with built-in fault n Output Short Circuit Protection protection features to aid in protecting against output shorts, n Wide Input Range: 2.5V to 16V Operating, input/output overvoltage, and overtemperature conditions. 40V Maximum Transient The part consists of a 42V master switch, and a 42V slave n LT3579-1: Dual-Phase Capable switch that can be tied together for a total current limit of 6A. n Master/Slave (3.4A/2.6A) Switch Design The LT3579 is ideal for many local power supply designs. It n User Configurable Undervoltage Lockout can be easily configured in Boost, SEPIC, Inverting, or Flyback n Easily Configurable as a Boost, SEPIC, Inverting, or configurations, and is capable of generating 12V at 1.7A, or Flyback Converter –12V at 1.2A from a 5V input. In addition, the LT3579’s slave n Low VCESAT Switch: 250mV at 5.5A (Typical) switch al ows the part to be configured in high voltage, high n Can Be Synchronized to External Clock power charge pump topologies that are very efficient and n Can Synchronize other Switching Regulators require fewer components than traditional circuits. n High Gain SHDN Pin Accepts Slowly Varying Input Signals The LT3579’s switching frequency range can be set bet- n 20-Lead TSSOP and 20-Pin 4mm × 5mm QFN ween 200kHz and 2.5MHz. The part may be clocked inter- Packages nally at a frequency set by the resistor from the RT pin to ground, or it may be synchronized to an external clock. A buffered version of the clock signal is driven out of APPLICATIONS the CLKOUT pin, and may be used to synchronize other n compatible switching regulator ICs to the LT3579. Local Power Supply n Vacuum Fluorescent Display (VFD) Bias Supplies The LT3579 also features innovative SHDN pin circuitry n TFT-LCD Bias Supplies that allows for slowly varying input signals and an adjust- n Automotive Engine Control Unit (ECU) Power able undervoltage lockout function. Additional features All registered trademarks and trademarks are the property of their respective owners. Protected such as frequency foldback and soft-start are integrated. by U.S. Patents, including 7579816. The LT3579 is available in 20-lead TSSOP and 20-pin 4mm × 5mm QFN packages. TYPICAL APPLICATIONEfficiency and Power Loss1MHz, 5V to 12V Boost Converter with Output Short Circuit Protection 100 3.2 2.2µH 90 2.8 V VOUT IN 5V 12V 1.7A 80 2.4 10µF POWER LOSS (W) SW1 SW2 130k 6.3k 10µF 70 2.0 V FB IN 22µF 60 1.6 100k FAULT GATE VIN 200k LT3579 EFFICIENCY (%) 50 1.2 SHDN TEMPERATURE CLKOUT MONITOR 40 0.8 RT VC SYNC GND SS 8k 30 0.4 86.6k 0.1µF 47pF 2.2nF 20 0 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 35791 TA01 LOAD CURRENT (A) 35791 TA02 Rev. B Document Feedback 1 For more information www.analog.com Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram State Diagram Operation Applications Information Appendix Typical Application Package Description Typical Application Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram State Diagram Operation Applications Information Appendix Typical Application Package Description Revision History Typical Application Related Parts
