Features and Benefits
- Drives Up to 20 White LEDs (10 in Series per Converter) from a 3.6V Supply
- Two Independent Step-Up Converters Capable of Driving Asymmetric LED Strings
- Independent Dimming and Shutdown Control of the Two LED Strings
- Internal Schottky Diodes
- Internal Soft-Start Eliminates Inrush Current
- Open LED Protection (39.5V Max VOUT)
- Fixed Frequency Operation Up to 2MHz
- 81% Efficiency Driving 16 White LEDs at 15mA (Eight per Driver) from a 3.6V Supply
- Wide Input Voltage Range: 2.7V to 24V
- Available in 10-Pin DFN and 16-Pin Thermally Enhanced TSSOP Packages
LT3466 is a dual full function step-up DC/DC converter specifically designed to drive up to 20 White LEDs (10 in series per converter) with a constant current. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for ballast resistors and expensive factory calibration.
The two independent converters are capable of driving asymmetric LED strings. The dimming of the two LED strings can also be controlled independently. The LT3466 is ideal for providing backlight for main and sub-displays in cell phones and other handheld devices.
The LT3466 operating frequency can be set with an external resistor over a 200kHz to 2MHz range. A low 200mV feedback voltage minimizes power loss in the current setting resistor for better efficiency. Additional features include output voltage limiting when LEDs are disconnected and internal soft-start.
The LT3466 is available in the 10-pin (3mm × 3mm × 0.75mm) DFN and 16-pin thermally enhanced TSSOP packages.
- Main/Sub Displays
- Digital Cameras, Sub-Notebook PCs
- PDAs, Handheld Computers
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 DC915 features the LT3466-1 high efficiency boost white LED driver and a step-up converter. There is one LED driver output for 6 or 8 WLEDs and a separate DC/DC converter that generates outputs for the LCD bias. VO1 drives 8 LEDs in series with 15mA LED current and VO2/VO3 can delivery ±15V at 10mA current. If the charge-pump circuitry which generates VO3 is removed (C4, C5 and D1), VO2 can deliver over 35mA of current. The input voltage range is 3V to 14V, but can go as low as 2.7V with slightly reduced output current.
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:
LT3466 Companion Parts
Recommended Related Parts
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.