Overview
Features and Benefits
- 3000:1 True Color PWM™ Dimming for LEDs
- Wide VIN Range: 4.5V to 40V
- Rail-to-Rail Current Sense Range: 0V to 40V
- Internal 40V/5A Switch
- Programmable PWM Dimming Signal Generator
- Constant Current (±3%) and Constant-Voltage (±2%) Regulation
- Accurate Analog Dimming
- Drives LEDs in Boost, SEPIC, CUK, Buck Mode, Buck-Boost Mode, or Flyback Configuration
- Output Short-Circuit Protected Boost
- Open LED Protection and Reporting
- Adjustable Switching Frequency: 100kHz to 1MHz
- Programmable VIN UVLO with Hysteresis
- C/10 Indication for Battery Chargers
- Low Shutdown Current: <1μA
- Thermally Enhanced 5mm × 6mm QFN Package
Product Details
The LT3954 is a DC/DC converter designed to operate as a constant-current source and constant-voltage regulator. It features an internal low side N-channel MOSFET rated for 40V/5A. The LT3954 is ideally suited for driving high current LEDs, but also has features to make it suitable for charging batteries and supercapacitors. The fixed frequency, current mode architecture results in stable operation over a wide range of supply and output voltages. A voltage feedback pin serves as the input for several LED protection features, and also makes it possible for the converter to operate as a constant-voltage source. A frequency adjust pin allows the user to program the frequency from 100kHz to 1MHz to optimize efficiency, performance or external component size.
The LT3954 senses output current at the high side or at the low side of the load. The internal PWM generator can be configured to self-oscillate at fixed frequency with duty ratio programmable from 4% to 96%. When driven by an external signal, the PWM input provides LED dimming ratios of up to 3000:1. The CTRL input provides additional analog dimming capability.
Applications
- High Power LEDs
- Output Short-Circuit Protected Boost
- Battery and SuperCap Chargers
- Accurate Current Limited Voltage Regulators
Product Categories
Markets & Technology
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)
Evaluation Kit Manuals (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.
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.
Models for the following parts are available in LTspice:
Product Recommendations
LT3954 Companion Parts
Recommended Related Parts
Reference Materials
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.
Support & Discussions
LT3954 Discussions
Sample & Buy
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 Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
