LT3476 - High Current Quad Output LED Driver

Features

  • True Color PWM Dimming Delivers Up to 5000:1 Dimming Ratio (In Boost Configuration)
  • LED Current Regulation with High-Side Sense
  • VADJ Pin Accurately Sets LED Current Sense Threshold Over Range 10mV to 120mV
  • Four Independent Driver Channels with 1.5A, 36V Internal NPN Switches
  • Frequency Adjust Pin: 200kHz to 2MHz
  • High Efficiency Conversion = Up to 96%
  • Open LED Protection
  • Low Shutdown Current < 10μA
  • Wide VIN Range: 2.8V to 16V
  • Thermally Enhanced, 38-Lead, 5mm × 7mm QFN Package
Designed for Automotive and Transportation Applications
AEC-Q100 generic family data available for specific packages


Typical Application

LT3476 Typical Application
LT3476 Typical Application

Description

The LT3476 is a quad output DC/DC converter designed to operate as a constant-current source for driving high current LEDs. A fixed frequency, current mode architecture results in stable operation over a wide range of supply and output voltages. A frequency adjust pin allows the user to program switching frequency between 200kHz and 2MHz to optimize efficiency and external component size. The LT3476 senses output current at the high side of the LED. High side current sensing is the most flexible scheme for driving LEDs, allowing buck, boost or buckboost configurations. Each current monitor threshold is trimmed to within 2.5% at the full scale of 105mV. With an external sense resistor, the user programs the output current range of each channel. Each of the four regulators is independently operated by that channel’s PWM signal. This PWM feature allows precise adjustment of the color mixing or dimming ratio of the LED source. Dimming ratios up to 1000:1 can be achieved.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LT3476EUHF#PBF 5x7 QFN-38 UHF E 05-08-1701 Yes
LT3476EUHF#TRPBF 5x7 QFN-38 UHF E 05-08-1701 Yes
LT3476IUHF#PBF 5x7 QFN-38 UHF I 05-08-1701 Yes
LT3476IUHF#TRPBF 5x7 QFN-38 UHF I 05-08-1701 Yes


LT3476 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LT3476EUHF#PBF 5x7 QFN-38 E $6.63 $4.64 Yes
LT3476EUHF#TRPBF 5x7 QFN-38 E $4.70 Yes
LT3476IUHF#PBF 5x7 QFN-38 I $7.63 $5.34 Yes
LT3476IUHF#TRPBF 5x7 QFN-38 I $5.40 Yes
Buy NowRequest Samples
* 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 Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC976A LT3476EUHF Demo Board | Quad Buck Mode LED Driver, PVIN ≤ 33V, Up to 27VLED @ 350mA or 1.05A $150.00
Buy Now
Click here to view our complete list of demo boards

Designed for Automotive and Transportation Applications

Please contact your local sales representative for more information regarding reliability reports and AEC-Q100 data or to inquire about parts that are not included. For more information, view our Automotive and Transportation page

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LT3476IUHF#PBF 5x7 QFN-38 I $7.63 $5.34 Yes
LT3476IUHF#TRPBF 5x7 QFN-38 I $5.40 Yes
Buy NowRequest Samples
* 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 Linear Technology sales office or authorized distributor.

Applications

  • RGGB Lighting
  • Automotive and Avionic Lighting
  • TFT LCD Backlighting
  • Constant-Current Sources

Product Notifications

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Design Tools

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

To launch a ready to run LTspice demonstration circuit for this part:

  • Step 1: If you have not installed LTspice on this computer, download and install LTspice
  • Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
  • Step 3: If LTspice does not automatically open after clicking the link above, 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

To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.

Models for the following parts are available in LTspice:
LT3476

Technical Support