Overview
Features and Benefits
- 5000:1 True Color PWM™ Dimming Ratio
- 1.5A, 45V Internal Switch
- 100mV High Side Current Sense
- Open LED Protection
- Adjustable Frequency: 250kHz to 2.5MHz
- Wide Input Voltage Range:
- Operation from 3V to 30V
- Transient Protection to 40V
- Operates in Boost, Buck Mode and Buck-Boost Mode
- Gate Driver for PMOS LED Disconnect
- Constant-Current and Constant-Voltage Regulation
- CTRL Pin Provides 10:1 Analog Dimming
- Low Shutdown Current: <1μA
- Available in (4mm × 4mm) 16-Lead QFN and 16-Pin TSSOP Packages
Product Details
The LT3517 is a current mode DC/DC converter with an internal 1.5A, 45V switch specifically designed to drive LEDs. The LT3517 operates as a LED driver in boost, buck mode and buck-boost mode. It combines a traditional voltage loop and a unique current loop to operate as a constant-current source or constant-voltage source. Programmable switching frequency allows optimization of the external components for efficiency or component size. The switching frequency of LT3517 can be synchronized to an external clock signal. The LED current is externally programmable with a 100mV sense resistor. The external PWM input provides up to 5000:1 LED dimming. The CTRL pin provides further 10:1 dimming ratio.
The LT3517 is available in the tiny footprint 16-lead QFN (4mm × 4mm) and the 16-pin TSSOP packages. The LT3517 provides a complete solution for both constant-voltage and constant-current applications.
Applications
- Display Backlighting
- Automotive and Avionic Lighting
- Illumination
- Scanners
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 (1)
Documentation & Resources
-
R518 Reliability Data3/26/2018
-
DC1279A - Demo Manual9/24/2009
Tools & Simulations
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.
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:
Product Recommendations
LT3517 Companion Parts
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.View our quality and reliability program and certifications for more information.
PCN-PDN Information
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Support & Discussions
LT3517 Discussions
Sample & Buy
Ordering FAQs
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Buy Now Pricing
(**) Displayed Buy Now Price and Price Range is based on small quantity orders.
List Pricing
(*)The 1Ku 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. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
Lead Times
Please see the latest communication from our CCO regarding lead times.
Sampling
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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.