Features and Benefits
- 6A, 42V Combined Power Switch
- Output Short Circuit Protection
- Wide Input Range: 2.5V to 16V Operating, 40V Maximum Transient
- LT3579-1: Dual-Phase Capable
- Master/Slave (3.4A/2.6A) Switch Design
- User Configurable Undervoltage Lockout
- Easily Configurable as a Boost, SEPIC, Inverting, or
- Flyback Converter
- Low VCESAT Switch: 250mV at 5.5A (Typical)
- Can Be Synchronized to External Clock
- Can Synchronize other Switching Regulators
- High Gain SHDN Pin Accepts Slowly Varying Input Signals
- 20-Lead TSSOP and 20-Pin 4mm × 5mm QFN Packages
The LT3579 is a PWM DC/DC converter with built-in fault protection features to aid in protecting against output shorts, input/output overvoltage, and overtemperature conditions. The part consists of a 42V master switch, and a 42V slave switch that can be tied together for a total current limit of 6A.
The LT3579 is ideal for many local power supply designs. It can be easily configured in Boost, SEPIC, Inverting, or Flyback configurations, and is capable of generating 12V at 1.7A, or –12V at 1.2A from a 5V input. In addition, the LT3579’s slave switch allows the part to be configured in high voltage, high power charge pump topologies that are very efficient and require fewer components than traditional circuits.
The LT3579’s switching frequency range can be set between 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 version of the clock signal is driven out of the CLKOUT pin, and may be used to synchronize other compatible switching regulator ICs to the LT3579.
The LT3579 also features innovative SHDN pin circuitry that allows for slowly varying input signals and an adjustable undervoltage lockout function. Additional features such as frequency foldback and soft-start are integrated. The LT3579 is available in 20-lead TSSOP and 20-pin 4mm × 5mm QFN packages.
- Local Power Supply
- Vacuum Fluorescent Display (VFD) Bias Supplies
- TFT-LCD Bias Supplies
- Automotive Engine Control Unit (ECU) Power
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (2)
Demonstration circuit 1661A features the LT3579 and LT3579-1 in a parallel boost regulator configuration. The circuit is designed to convert a 5V to 10V input source to 12V at 3.5A. DC1661A is designed to survive output short circuit events with an external disconnect MOSFET at the output as default.
Demonstration circuit 1514A feature the LT3579 in A Boost Regulator configuration. The Boost is designed to convert a 5V to 10V input source to 12V at 1.75A. DC1514A is designed to survive output short circuit events with the external MOSFET installed at the input as default. The board includes an option to install the MOSFET at the output side. The LT3579 includes a 42V Master and Slave switch combination with 6A total current and can be used in many configurations such as Boost, SEPIC, Cuk and Flyback.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.
Models for the following parts are available in LTspice:
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
Design tools for the following parts are available in LTpowerCAD:
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.