Features and Benefits
- True Color PWM™ Dimming Delivers Up to 3000:1 Dimming Ratio
- Built-In Gate Driver for PMOS LED Disconnect
- Three Independent Driver Channels with 600mA, 60V Internal Switches
- Operates in Buck, Boost, Buck-Boost Modes
- CTRL Pin Accurately Sets LED Current Sense Threshold Over a Range of 10mV to 100mV
- Adjustable Frequency: 330kHz to 2.1MHz
- Open LED Protection
- Wide Input Voltage Range:
- Operation from 3V to 30V
- Transient Protection to 40V
- Surface Mount Components
- 28-Lead (4mm × 5mm) QFN and TSSOP Packages
The LT3492 is a triple output DC/DC converter designed to operate as a constant-current source and is ideal for driving LEDs. The LT3492 works in buck, boost or buck-boost mode. The LT3492 uses a fixed frequency, current mode architecture resulting in stable operation over a wide range of supply and output voltages. A frequency adjust pin allows the user to program switching frequency between 330kHz and 2.1MHz to optimize efficiency and external component size.
The external PWM input provides 3000:1 LED dimming on each channel. Each of the three channels has a built-in gate driver to drive an external LED-disconnect P-channel MOSFET, allowing high dimming range. The output current range of each channel of the LT3492 is programmed with an external sense resistor.
The CTRL pin is used to adjust the LED current either for analog dimming or over-temperature protection.
- RGB Lighting
- Billboards and Large Displays
- Automotive and Avionic Lighting
- Constant-Current Sources
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)
Demonstration circuit 1405 is a Triple Boost or Buck/Boost LED Driver featuring the LT3492. The LT3492 is a triple output DC/DC converter designed to operate as current sources for driving LEDs using . Each of the three regulators on the demo board is independently operated. The board can be configured with either boost (default) or buck-boost mode; buck mode is not supported. The current for each output is 61mA in either mode.
The IC's input voltage range is 8V to 30V with 40V transient protection; however the LEDs input power source can be as high as 40V. The overvoltage protection (open LED detect) is set at 58V. For a typical application with a LED voltage of 3.6V, each boost circuit can drive around 15 LEDs. Applications with different input voltages and load combinations can be demonstrated on this circuit with some board modifications.
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.
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:
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.