Overview

Features and Benefits

  • Operates in Boost, SEPIC, Buck Mode and Buck-Boost Mode
  • 128:1 Internal Exponential Scale PWM Dimming
  • Wide Input Voltage Range (3V to 60V)
  • 1.5A, 60V Internal Switch
  • 20000:1 External PWM Dimming at 100Hz
  • ±2% LED Current and Output Voltage Regulation
  • PMOS Switch Driver for PWM Dimming
  • LED Short/Open Protection and Indication
  • Constant Voltage and Constant Current Regulation
  • Adjustable 300kHz to 2MHz Switching Frequency
  • Adjustable 100Hz to 1kHz PWM Generator Frequency
  • Internal Spread Spectrum Frequency Modulation
  • Easy Synchronization to External Clock
  • Programmable VIN UVLO with Hysteresis
  • Available in 16-Lead MSOP Package

Product Details

The LT3950 is a multitopology DC/DC converter designed specifically to drive high current LEDs. It contains a 1.5A, 60V DMOS switch and supports an external PWM dimming PMOS. The LT3950 has an internal PWM generator for dimming that maps an analog control signal to an exponential scale used to define PWM dimming duty ratio. Using an exponential scale to define duty ratio preserves dimming resolution across a wide range of LED current. In addition to operating as a constant current source, the LT3950 also provides output voltage regulation. This can be used to prevent damage to the part in case of open LED events. A programmable switching frequency offers flexibility in design for higher efficiency or reduced component size. Enabling spread spectrum frequency modulation reduces EMI. The switching frequency can also easily be synchronized by driving the SYNC/SPRD pin with an external clock. LED current is programmed with a single external sense resistor and can be adjusted from zero to full-scale by an analog signal at the CTRL pin.

APPLICATIONS

  • Display Backlighting
  • Automotive and Avionic Lighting

Product Lifecycle icon-recommended Recommended for New Designs

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.

Evaluation Kits (1)

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LTspice

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.

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Models for the following parts are available in LTspice:

LT3950

Design Resources

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.

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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.


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Evaluation Boards Pricing displayed is based on 1-piece.
Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.