LT3956 - 80VIN, 80VOUT Constant-Current, Constant-Voltage Converter
- 3000:1 True Color PWM™ Dimming
- Wide Input Voltage Range: 4.5V to 80V
- Output Voltage Up to 80V
- Internal 3.3A/84V Switch
- Constant-Current and Constant-Voltage Regulation
- 250mV High Side Current Sense
- Drives LEDs in Boost, Buck Mode, Buck-Boost Mode, SEPIC or Flyback Topology
- Adjustable Frequency: 100kHz to 1MHz
- Open LED Protection
- Programmable Undervoltage Lockout with Hysteresis
- Constant-Voltage Loop Status Pin
- PWM Disconnect Switch Driver
- CTRL Pin Adjusts High Side Current Sense Threshold
- Low Shutdown Current: <1μA
- Programmable Soft-Start
- Available in the 36-Lead (5mm × 6mm) QFN Package
AEC-Q100 data available for specific packages
The LT3956 is a DC/DC converter designed to operate as a constant-current source and constant-voltage regulator. It is ideally suited for driving high current LEDs. It features an internal low side N-channel power MOSFET rated for 84V at 3.3A and driven from an internal regulated 7.15V supply. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages. A ground referenced voltage FB 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 LT3956 senses output current at the high side of the LED string. High side current sensing is the most flexible scheme for driving LEDs, allowing boost, buck mode or buck-boost mode configuration. The PWM input provides LED dimming ratios of up to 3000:1, and the CTRL input provides additional analog dimming capability.
CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.
For complete and up to date package information and drawings, please refer to our packaging page
- Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
- Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
- Please refer to our general ordering information or the product datasheet for more details
Package Variations and Pricing
|Buy Now • Request Samples|
Demo BoardsLinear 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.
|DC1521A||LT3956UHE Demo Board | 80Vin, 80Vout Constan-Current, Constant-Voltage Converter||$175.00|
Designed for Automotive and Transportation ApplicationsAEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page
|Buy Now • Request Samples|
- High Power LED
- Battery Charger
- Accurate Current Limited Voltage Regulator
People Who Viewed This Product Also Viewed
- LT3796/LT3796-1 - 100V Constant-Current and Constant-Voltage Controller with Dual Current Sense
- LT3761/LT3761-1 - 60VIN LED Controller with Internal PWM Generator
- LTM8042/LTM8042-1 - μModule (Power Module) Boost LED Driver and Current Source
- LT3756/LT3756-1/LT3756-2 - 100VIN, 100VOUT LED Controller
- LT3518 - Full-Featured LED Driver with 2.3A Switch Current
- LT3791 - 60V 4-Switch Synchronous Buck-Boost LED Driver Controller
- LT3478 - 4.5A Monolithic LED Drivers with True Color PWM Dimming
- LT8705 - 80V VIN and VOUT Synchronous 4-Switch Buck- Boost DC/DC Controller
- LTC3783 - PWM LED Driver and Boost, Flyback and SEPIC Converter
- LT3477 - 3A, DC/DC Converter with Dual Rail-to-Rail Current Sense
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.
LTspice® software 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
To launch a ready to run LTspice demonstration circuit for this part:
- Step 1: If you have not installed LTspice on this computer, download and install LTspice
- Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
- Step 3: If LTspice does not automatically open after clicking the link above, 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
To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.
Models for the following parts are available in LTspice: