Features and Benefits
- 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
The LT3964 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.
- General Purpose, Industrial, Medical and Automotive Lighting
- Constant-Current, Constant-Voltage Source
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)
The DC2424A is a 36V synchronous dual LED driver with I2C featuring the LT3964. It drives two separate LEDs (or channels of LEDs) at 1A when VIN is between 5V and 36V. DC2424A runs at 2MHz switching frequency. Its two channels can drive separate LED strings which can have different currents, voltages, or dimming ratios. It can be controlled with I2C communications or it can be run in non-I2C mode with proper ADDR pin settings. It is protected against both open and short LED conditions and reports the faults. In I2C mode, faults can be enabled or disabled. Up to 9 different DC2424As can be placed on the same I2C bus with unique addresses. A graphical user interface (GUI) is available through QuikEval™ when connected to a DC2026C Linduino® One demo circuit.
Tools & Simulations
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.
Models for the following parts are available in LTspice:
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.
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.