Overview
Features and Benefits
- Eight Independent 17V 330mΩ NMOS Switches
- Independent On/Off/Dimming Control of 1 to 4 LEDs for Each Switch
- I2C Multidrop Serial Interface with Programmable Open LED and Shorted LED Fault Reporting
- 16 Unique I2C Addresses
- VDD Range: 2.7V to 5.5V and VIN Range: 8V to 60V
- Digital Programmable 256:1 PWM Dimming
- Fade Transition Between PWM Dimming States
- Optional Internal Clock Generator or External Clock Source for PWM Dimming
- Open LED Overvoltage Protection
- Flicker Free PWM Dimming
- AEC-Q100 Qualified for Automotive Applications
Product Details
The LT3965/LT3965-1 is an LED bypass switching device for dimming individual LEDs in a string using a common current source. It features eight individually controlled floating source 17V/330mΩ NMOS switches. The eight switches can be connected in parallel and/or in series to bypass current around one or more LEDs in a string. The LT3965 is initialized with all switches off (LEDs on), and the LT3965-1 is initialized with all switches on (LEDs off)The LT3965/LT3965-1 uses the I2C serial interface to communicate with the microcontroller. Each of the eight channels can be independently programmed to bypass the LED string in constant on or off, or PWM dimming with or without fade transition. Using the fade option provides 11-bit resolution logarithmic transition between PWM dimming states. The LT3965/LT3965-1 provides an internal clock generator and also supports external clock source for PWM dimming. The LT3965/LT3965-1 reports fault conditions for each channel such as open LED and shorted LED. The four address select pins allow 16 LT3965/LT3965-1 devices to share the I2C bus. The device is available in a 28-lead TSSOP package.
Applications
- Automotive LED Headlight Clusters
- Large LED Displays
- Automated Camera Flash Equipment
- RGBW Color Mixing Lighting
Product Categories
Markets and Technologies
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 & Resources
-
DC2218A - Demo Manual12/16/2015
-
Matrix LED Dimmer2/10/2016
Tools & Simulations
Linduino
Linduino is Analog Devices’ Arduino compatible system for developing and distributing firmware libraries and example code for our integrated circuits. Each Linduino-supported product includes an example main program, defined in the LTSketchbook/Part Number folder and driver code, defined in the LTSketchbook/libraries folder.
Linduino code repository on GitHub and instructions on how to use the code.

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.View our quality and reliability program and certifications for more information.
PCN-PDN Information
Select a model from the dropdown below to subscribe to PCN/PDN notifications and view past notifications as well.
Support & Discussions
LT3965 Discussions
Sample & Buy
Ordering FAQs
See our Ordering FAQs for answers to questions about online orders, payment options and more.
Buy Now Pricing
(**) Displayed Buy Now Price and Price Range is based on small quantity orders.
List Pricing
(*)The 1Ku 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. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
Lead Times
Please see the latest communication from our CCO regarding lead times.
Sampling
Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.
Evaluation Boards
Pricing displayed is based on 1-piece.
Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.