LT3743
High Current Synchronous Step-Down LED Driver with Three-State Control
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Overview
Features and Benefits
- PWM Dimming Provides Up to 3000:1 Dimming Ratio
- CTRL_SEL Dimming Provides Up to 3000:1 Dimming Ratio Between Any Current
- Three-State Current Control for Color Mixing
- ±6% Current Regulation Accuracy
- 6V to 36V Input Voltage Range
- Average Current Mode Control
- 2μs Maximum Recovery Time Between Any Current Regulation State
- <1μA Shutdown Current
- Output Voltage Regulation and Open-LED Protection
- Thermally Enhanced 4mm × 5mm QFN and 28-Pin FE Package
Product Details
The LT3743 is a fixed frequency synchronous step-down DC/DC controller designed to drive high current LEDs. The average current mode controller will maintain inductor current regulation over a wide output voltage range of 0V to (VIN – 2V). LED dimming is achieved through analog dimming on the CTRL_L, CTRL_H and CTRL_T pins and with PWM dimming on the PWM and CTRL_SEL pins. Through the use of externally switched load capacitors, the LT3743 is capable of changing regulated LED current levels within several μs, providing accurate, high speed PWM dimming between two current levels. The switching frequency is programmable from 200kHz to 1MHz through an external resistor on the RT pin.
Additional features include voltage regulation and overvoltage protection set with a voltage divider from the output to the FB pin. Overcurrent protection is provided and set by the CTRL_H pin.
Applications
- DLP Projectors
- High Power Architectural Lighting
- Laser Diodes
Product Categories
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
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R548 Reliability Data3/26/2018PDF28 K
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DC1470A - Demo Manual9/16/2015PDF273K
Tools & Simulations
LTspice
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To launch ready-to-run LTspice demonstration circuits for this part:
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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:
LT3743
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.
| Part Number | Material Declaration | Reliability Data | Pin/Package Drawing | CAD Symbols, Footprints & 3D Models |
|---|---|---|---|---|
| LT3743EFE#PBF | Material Declaration | Reliability Data | 28-Lead TSSOP w/ EP | |
| LT3743EFE#TRPBF | Material Declaration | Reliability Data | 28-Lead TSSOP w/ EP | |
| LT3743EUFD#PBF | Material Declaration | Reliability Data | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | |
| LT3743EUFD#TRPBF | Material Declaration | Reliability Data | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | |
| LT3743IFE#PBF | Material Declaration | Reliability Data | 28-Lead TSSOP w/ EP | |
| LT3743IFE#TRPBF | Material Declaration | Reliability Data | 28-Lead TSSOP w/ EP | |
| LT3743IUFD#PBF | Material Declaration | Reliability Data | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | |
| LT3743IUFD#TRPBF | Material Declaration | Reliability Data | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | |
| Wafer Fabrication Data | R548 Reliability Data |
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Sample & Buy
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Evaluation Boards
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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.