LT3741/LT3741-1 - High Power, Constant Current, Constant Voltage, Step-Down Controller

Features

  • Control Pin Provides Accurate Control of Regulated Output Current
  • ±1.5% Voltage Regulation Accuracy
  • ±6% Current Regulation Accuracy
  • 6V to 36V Input Voltage Range
  • Wide Output Voltage Range Up to (VIN – 2V)
  • Average Current Mode Control
  • <1μA Shutdown Current
  • Up to 94% Efficiency
  • Additional Pin for Thermal Control of Load Current
  • Thermally Enhanced 4mm × 4mm QFN and 20-Pin FE Package

Typical Application

LT3741 Typical Application
LT3741 Typical Application

Description

The LT®3741 and LT3741-1 are fixed frequency synchronous step-down DC/DC controllers designed to accurately regulate the output current at up to 20A. The average currentmode controller will maintain inductor current regulation over a wide output voltage range of 0V to (VIN – 2V). The regulated current is set by an analog voltage on the CTRL pins and an external sense resistor. Due to its unique topology, the LT3741 is capable of sourcing and sinking current. If sinking current is not required, or for parallel applications, use the LT3741-1. The regulated voltage and overvoltage protection are set with a voltage divider from the output to the FB pin. Soft-Start is provided to allow a gradual increase in the regulated current during startup. The switching frequency is programmable from 200kHz to 1MHz through an external resistor on the RT pin or through the use of the SYNC pin and an external clock signal.

Additional Features include an accurate external reference voltage for use with the CTRL pins, an accurate UVLO/EN pin that allows for programmable UVLO hysteresis, and thermal shutdown.

Packaging

For complete and up to date package information and drawings, please refer to our packaging page

QFN-20

LT3741 Package Drawing
LT3741 Package Drawing

Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price (1-99) Price (1k)* RoHS Data
LT3741EFE#PBF TSSOP 20 E $5.86 $4.10 View
LT3741EFE#TRPBF TSSOP 20 E $4.16 View
LT3741EUF#PBF QFN 20 E $5.64 $3.95 View
LT3741EUF#TRPBF QFN 20 E $4.01 View
LT3741IFE#PBF TSSOP 20 I $6.89 $4.82 View
LT3741IFE#TRPBF TSSOP 20 I $4.88 View
LT3741IUF#PBF QFN 20 I $6.64 $4.65 View
LT3741IUF#TRPBF QFN 20 I $4.71 View
Buy NowRequest Samples
* The USA 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 Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC1602A LT3741EFE Demo Board | High Power Constant Current Constant Voltage, Synchronous Step-Down Controller. $175.00
Buy Now
Click here to view our complete list of demo boards

Applications

  • General Purpose Industrial
  • Super-Cap Charging
  • Applications Needing Extreme Short-Circuit Protection and/or Accurate Output Current Limit
  • Constant Current or Constant Voltage Source

Product Notifications

Please login to your MyLinear account for notifications of datasheet updates, new document releases and LTspice model announcements for your favorite products. If you do not have a MyLinear account you may Sign Up Now.

Forgot your password? Click here.
Need help? Email mylinear@linear.com with questions and comments.

Design Tools

LTspiceIV

LTspice IV is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice IV

To launch a ready to run LTspice demonstration circuit for this part:

To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.

Models for the following parts are available in LTspice IV:
LT3741

Technical Support