IC manufacturers Analog Devices

IC manufacturers (103)

Analog Devices LT3743

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

Overview

TopologyBuck Converter
Input voltage6-36 V
Switching frequency200-1000 kHz
IC revisionE

Description

The LT®3743 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.

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

Typical applications

  • DLP Projectors
  • Laser Diodes
  • High Power Architectural Lighting

Products

Order Code
Data­sheet
Simu­lation
Downloads
Status
Product series
L(µH)
IRP,40K(A)
ISAT,10%(A)
ISAT,30%(A)
RDC(mΩ)
fres(MHz)
Material
Qty.
RDC max.(mΩ)
LR(µH)
SamplesAvailability & Sample
SPECWE-HCC SMT High Current Cube Inductor, 1 µH, 34 A
Simu­lation
Availability
Status Activei| Production is active. Expected lifetime: >10 years.
Inductance1 µH
Performance Rated Current34 A
Saturation Current @ 10%30.6 A
Saturation Current @ 30%33.5 A
Self Resonant Frequency96 MHz
MaterialFerrite 
Packaging Unit300 
DC Resistance2.5 mΩ
Rated Inductance0.9 µH
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SPECWE-HCI SMT Flat Wire High Current Inductor, 1.3 µH, 32.1 A
Simu­lation
Availability
Status Activei| Production is active. Expected lifetime: >10 years.
Inductance1.3 µH
Performance Rated Current32.1 A
Saturation Current @ 10%11 A
Saturation Current @ 30%25 A
DC Resistance1.8 mΩ
Self Resonant Frequency59 MHz
MaterialWE-PERM 
Packaging Unit400 
DC Resistance1.87 mΩ
Rated Inductance0.9 µH
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SPECWE-HCI SMT Flat Wire High Current Inductor, 3.7 µH, 18.3 A
Simu­lation
Availability
Status Activei| Production is active. Expected lifetime: >10 years.
Inductance3.7 µH
Performance Rated Current18.3 A
Saturation Current @ 10%7 A
Saturation Current @ 30%16 A
DC Resistance4.9 mΩ
Self Resonant Frequency26 MHz
MaterialWE-PERM 
Packaging Unit400 
DC Resistance5.39 mΩ
Rated Inductance2.6 µH
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SPECWE-HCI SMT Flat Wire High Current Inductor, 11.3 µH, 13.1 A
Simu­lation
Availability
Status Activei| Production is active. Expected lifetime: >10 years.
Inductance11.3 µH
Performance Rated Current13.1 A
Saturation Current @ 10%4 A
Saturation Current @ 30%9.5 A
DC Resistance9.1 mΩ
Self Resonant Frequency12 MHz
MaterialWE-PERM 
Packaging Unit400 
DC Resistance10.01 mΩ
Rated Inductance7.5 µH
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