Features and Benefits
- Wide VIN Range: 1.6V to 42V
- Positive or Negative Output Voltage Programming with a Single Feedback Pin
- PGOOD Output Voltage Status Report
- Accurate 50mV SENSE Threshold Voltage
- Programmable Soft-Start
- Programmable Operating Frequency (100kHz to 1MHz) with One External Resistor
- Synchronizable to an External Clock
- Low Shutdown Current < 1μA
- INTVCC Regulator Supplied from VIN or DRIVE
- Programmable Input Undervoltage Lockout with Hysteresis
The LT3759 is a wide input range, current mode, DC/DC controller which is capable of regulating either positive or negative output voltages from a single feedback pin. It can be configured as a boost, SEPIC or inverting converter.
The LT3759 drives a low side external N-channel power MOSFET. An internal LDO regulator draws power from VIN or DRIVE to provide up to a 4.75V supply for the gate driver. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages. The operating frequency of LT3759 can be set over a 100kHz to 1MHz range with an external resistor, or can be synchronized to an external clock using the SYNC pin.
The LT3759 features soft-start and frequency foldback functions to limit inductor current during start-up and output short-circuit. A window comparator on the FBX pin reports via the PGOOD pin, providing output voltage status indication. The device is available in a 12-Lead exposed pad MSOP package.
- Datacom and Industrial Boost, SEPIC and Inverting Converters
- Distributed Power Supplies
- Portable Electronic Equipment
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 1787A is a wide input voltage range SEPIC converter featuring the LT3759 controller. It converts a 2.8V~36V input to a 12V output, with 1A load current capability for VIN ≥ 4V. The converter operates at a 300 kHz nominal switching frequency, with 91% peak efficiency. The DC1787A can be easily modified to generate other output voltages, and can also be optimized for efficiency and size with narrower input voltage ranges.
Demonstration circuit 1725A features LT3759 in a 485kHz boost converter, designed for a 5V/2A output from a 1.8V to 4.5V input. The LT3759 is a current mode DC/DC Boost/SEPIC/Inverting controller operating over an input range of 1.6V to 42V. Thanks to a novel FBX pin architecture, the LT3759 allows both positive and negative output feedback voltages.
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:
LT3759 Companion Parts
Recommended Suggested Oscillator
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Sample & Buy
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