LT3743
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LT3743

High Current Synchronous Step-Down LED Driver with Three-State Control

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Info: : PRODUCTION tooltip
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Part Details
Part Models 8
1ku List Price Starting From $5.72
Features
  • 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
Additional Details
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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
Part Models 8
1ku List Price Starting From $5.72

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Documentation

Documentation

Video

Part Model Pin/Package Drawing Documentation CAD Symbols, Footprints, and 3D Models
LT3743EFE#PBF
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LT3743EFE#TRPBF
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LT3743EUFD#PBF
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LT3743EUFD#TRPBF
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LT3743IFE#PBF
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LT3743IFE#TRPBF
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LT3743IUFD#PBF
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LT3743IUFD#TRPBF
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Product Lifecycle

PCN

Apr 6, 2022

- 22_0068

Laser Top Mark for ETSSOP and TSSOP Packages Assembled in ADPG [PNG] and UTL

LT3743EFE#PBF

PRODUCTION

LT3743EFE#TRPBF

PRODUCTION

LT3743IFE#PBF

PRODUCTION

LT3743IFE#TRPBF

PRODUCTION

Jan 20, 2022

- 21_0269

Addition of Alternate Assembly Site ASE Taiwan for Select LFCSP Products

LT3743EUFD#PBF

PRODUCTION

LT3743EUFD#TRPBF

PRODUCTION

LT3743IUFD#PBF

PRODUCTION

LT3743IUFD#TRPBF

PRODUCTION

Filter by Model

reset

Reset Filters

Part Models

Product Lifecycle

PCN

Apr 6, 2022

- 22_0068

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Laser Top Mark for ETSSOP and TSSOP Packages Assembled in ADPG [PNG] and UTL

LT3743EFE#PBF

PRODUCTION

LT3743EFE#TRPBF

PRODUCTION

LT3743IFE#PBF

PRODUCTION

LT3743IFE#TRPBF

PRODUCTION

Jan 20, 2022

- 21_0269

arrow down

Addition of Alternate Assembly Site ASE Taiwan for Select LFCSP Products

LT3743EUFD#PBF

PRODUCTION

LT3743EUFD#TRPBF

PRODUCTION

LT3743IUFD#PBF

PRODUCTION

LT3743IUFD#TRPBF

PRODUCTION

Software & Part Ecosystem

Software & Part Ecosystem

Evaluation Kit

Evaluation Kits 1

reference details image

DC1470A

LT3743EUF Demo Board | High Current Step-Down LED Driver Controller, 6.5V ≤ VIN ≤ 24V, VLED = 6V @ 20A

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DC1470A

LT3743EUF Demo Board | High Current Step-Down LED Driver Controller, 6.5V ≤ VIN ≤ 24V, VLED = 6V @ 20A

LT3743EUF Demo Board | High Current Step-Down LED Driver Controller, 6.5V ≤ VIN ≤ 24V, VLED = 6V @ 20A

Product Detail

Demonstration circuit 1470 is a High Current Synchronous Step-Down LED Driver with Three-State Control featuring the LT3743EUFD. The demo board is optimized for 20A output from a 12V input. Being an LED driver, the output current is regulated until the output voltage reaches a programmed voltage limit. The voltage limit on this demo board is set to around 6V by resistors R5 and R6. The 6V is chosen because of the 6.3V voltage rating of the output capacitors.


The ideal load to be used with this demo board is a single LED, such as PT120 from Luminus Devices. The input voltage range of the LT3743 is 6V to 36V; however, the demo board utilizes 30V MOSFETs to demonstrate best efficiency, so the maximum recommended input voltage is 24V for the demo board.

Tools & Simulations

Tools & Simulations 1

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.

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