Features and Benefits
- Wide (1000:1) PWM Dimming Range with No ColorShift
- Independent Dimming and Shutdown Control of the LED Drivers
- Drives Up to 16 White LEDs at 25mA (8 per Driver) from a Single Li-Ion Cell
- Drives Up to 16 White LEDs at 100mA (8 per Driver) from 12V Supply
- ±3% LED Current Programming Accuracy
- Open LED Protection: 36V Clamp Voltage
- Fixed Frequency Operation: Up to 2.5MHz
- Wide Input Voltage Range: 2.5V to 24V
- Low Shutdown Current: ICC < 1μA
- Overtemperature Protection
- Available in (5mm × 3mm × 0.75mm) 16-Pin DFN and 16-Pin Thermally Enhanced TSSOP Packages
The LT3486 is a dual step-up DC/DC converter specifically designed to drive up to 16 White LEDs (8 in series per converter) at constant current from a single Li-Ion cell. Series connection of the LEDs provides identical LED currents resulting in uniform brightness. The two independent converters are capable of driving asymmetric LED strings.
The dimming of the two LED strings can be controlled independently via the respective CTRL pins. An internal dimming system allows the dimming range to be extended up to 1000:1 by feeding a PWM signal to the respective PWM pins. The LT3486 operating frequency can be set with an external resistor over a 200kHz to 2.5MHz range. A low 200mV feedback voltage (±3% accuracy) minimizes power loss in the current setting resistor for better efficiency. Additional features include output voltage limiting when LEDs are disconnected and overtemperature protection.
The LT3486 is available in a space saving 16-pin DFN (5mm × 3mm × 0.75mm) and 16-pin thermally enhanced TSSOP packages.
- Notebook PC Display
- LED Camera Light for Cell Phones
- Car Dashboard Lighting
- Avionics Displays
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 876 is a dual step-up white LED driver with wide dimming range featuring the LT3486. The board is optimized to drive a string of six, eight, or ten white LEDs at 100mA from each of its two outputs with a PVIN input voltage range of 3V to 25V. The maximum LED output voltage must be less than 36V as the overvoltage protection at the output will limit the maximum output voltage to 36V in the case of an open circuit load.
The high input voltage range, high-efficiency low-side internal 1.3A NPN power switches, ground-referenced low-voltage current sense resistors, PWM pins for 1000:1 dimming ratio, control pins for brightness adjust, overvoltage protection, shutdown control pin, externally programmable switching frequency, low shutdown current and internal soft-start capacitor make the LT3486 an extremely powerful and versatile LED driving IC for portable applications and displays.
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.