LT3964 - Dual 36V Synchronous 1.6A Buck LED Driver with I2C


  • Wide Input Voltage Range: 4V to 36V
  • Two Independent 1.6A/40V Synchronous Bucks
  • I2C Interface for Internal True Color PWM™ Dimming (8192:1), Analog Dimming and Fault Reporting
  • 1000:1 External True Color PWM Dimming and 10:1 External Analog Dimming
  • PMOS Switch Driver for PWM and Output Disconnect
  • ±3% Constant Current Regulation
  • Adjustable Frequency: 200kHz to 2MHz
  • Frequency Synchronization with Clock Output
  • Programmable OPENLED Protection with Reporting
  • Short-Circuit Protection with Reporting
  • Programmable Undervoltage Lockout with Hysteresis
  • Internal Compensation
  • 9 Unique Device Addresses for I2C
  • Available in 5mm × 6mm 36-Lead QFN Package

Typical Application

LT3964 Typical Application
LT3964 Typical Application


The LT®3964 is a dual synchronous step-down DC/DC converter with I2C interface designed to operate as a constant-current and constant-voltage source and is ideal for driving LEDs. The fixed frequency and peak current mode topology result in stable operation over a wide range of supply and output voltages. The ground referred voltage FB pin serves as the input for several LED protection features, and also allows the converter to operate as a constant-voltage source. The maximum output current is set by an external resistor, and the output current amplifier has a rail-to-rail common mode range. LT3964 uses an I2C interface to communicate with a microcontroller to read LED faults, write PWM and analog dimming registers and set fault masking. The I2C PWM input provides LED dimming ratios up to 8192:1. The I2C programmable CTRL register sets the gain of the external CTRL pin, and maximum current sense threshold, providing additional analog dimming capability.


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

Part Number Package Code Temp Package
LT3964EUHE#PBF 5x6 QFN-36 UHE E 05-08-1876 Yes
LT3964EUHE#TRPBF 5x6 QFN-36 UHE E 05-08-1876 Yes
LT3964HUHE#PBF 5x6 QFN-36 UHE H 05-08-1876 Yes
LT3964HUHE#TRPBF 5x6 QFN-36 UHE H 05-08-1876 Yes
LT3964IUHE#PBF 5x6 QFN-36 UHE I 05-08-1876 Yes
LT3964IUHE#TRPBF 5x6 QFN-36 UHE I 05-08-1876 Yes

LT3964 Package Drawing

Order Info

  • 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

Part Number Package Temp Price
LT3964EUHE#PBF 5x6 QFN-36 E $6.43 $4.50 Yes
LT3964EUHE#TRPBF 5x6 QFN-36 E $6.49 $4.56 Yes
LT3964HUHE#PBF 5x6 QFN-36 H $7.43 $5.20 Yes
LT3964HUHE#TRPBF 5x6 QFN-36 H $7.49 $5.26 Yes
LT3964IUHE#PBF 5x6 QFN-36 I $7.07 $4.95 Yes
LT3964IUHE#TRPBF 5x6 QFN-36 I $7.13 $5.01 Yes
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* 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
DC2424A LT3964 Demo Board | VIN = 5V to 36V driving two separate LED strings (1ALED/~3.6VLED) at 2MHz Contact Factory
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Click here to view our complete list of demo boards


  • General Purpose, Industrial, Medical and  Automotive Lighting
  • Constant-Current, Constant-Voltage Source

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Design Tools

Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:

  • LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
  • LTpowerCAD - A complete power supply selection, synthesis and design tool
  • LTpowerPlay - A development environment supporting Linear Technology's Digital Power System Management (PSM) products
  • PScope & QuikEval - USB-based product demonstration and data acquisition system for use with our ADCs, DACs, and more
  • Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
  • LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
  • And More!

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