Overview
Features and Benefits
- 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
Product Details
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.
Applications
- RGGB Lighting
- Automotive and Avionic Lighting
- TFT LCD Backlighting
- Constant-Current Sources
Product Categories
Markets and Technologies
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
Reliability Data (1)
User Guides (1)
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.
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Step 2: Click on the link in the section below to download a demonstration circuit.
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Models for the following parts are available in LTspice:
Reference Materials
Press Releases (1)
Technical Articles (1)
Design Resources
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Sample & Buy
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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.