Boost, Flyback, SEPIC and Inverting Controller
Features and Benefits
- Wide Input Voltage Range: 5.5V to 100V
- Positive or Negative Output Voltage Programming with a Single Feedback Pin
- Current Mode Control Provides Excellent Transient Response
- Programmable Operating Frequency (100kHz to 1MHz) with One External Resistor
- Synchronizable to an External Clock
- Low Shutdown Current < 1μA
- Internal 7.2V Low Dropout Voltage Regulator
- Programmable Input Undervoltage Lockout with Hysteresis
- Programmable Soft-Start
- Small 10-Lead DFN (3mm × 3mm) and MSOPE Packages
The LT3758/LT3758A are wide input range, current mode, DC/DC controllers which are capable of generating either positive or negative output voltages. They can be configured as either a boost, flyback, SEPIC or inverting converter. The LT3758/LT3758A drive a low side external N-channel power MOSFET from an internal regulated 7.2V supply. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages.
The operating frequency of LT3758/LT3758A can be set with an external resistor over a 100kHz to 1MHz range, and can be synchronized to an external clock using the SYNC pin. A minimum operating supply voltage of 5.5V, and a low shutdown quiescent current of less than 1μA, make the LT3758/LT3758A ideally suited for batterypowered systems.
The LT3758/LT3758A feature soft-start and frequency foldback functions to limit inductor current during start-up and output short-circuit. The LT3758A has improved load transient performance compared to the LT3758.
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 1342B features the LT3758AEMSE in a 300kHz SEPIC converter circuit, designed for a 24V output from a 18V to 72V input. The LT3758A operates over an input range of 5.5V to 100V, and features a novel FBX pin architecture, which allows it to be connected directly to a resistor divider from either a positive output voltage or a negative output voltage.
Demonstration circuit 1412A features the LT3758EMSE in a 300kHz Flyback converter circuit, designed for 3.3V/3A output from a 18V to 75V input. The LT3758EMSE operates over an input range of 5.5V to 100V, suitable for automotive, telecom and industrial applications. It also exhibits low shutdown quiescent current of 1μA, making them an ideal fit for battery-operated systems. Thanks to a novel FBX pin architecture, the LT3758EMSE can be connected directly to a divider from either a positive output or a negative output to ground.
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.