Features and Benefits
- Drives Up to Ten White LEDs from a 3V Supply
- High Side Sense Allows “One Wire Current Source”
- Internal Schottky Diode
- One Pin Dimming and Shutdown
- 80:1 True Color PWM™ Dimming Range
- 42V Open LED Protection
- 1MHz Switching Frequency
- ±5% Reference Accuracy
- VIN Range: 2.5V to 12V
- Requires Only 2.2µF Output Capacitor
- Low Profile 8-Lead DFN Package
- (3mm × 2mm × 0.75mm)
The LT3591 is a fixed frequency step-up DC/DC converter speciﬁcally designed to drive up to ten white LEDs in series from a Li-Ion cell. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for ballast resistors. The device features a unique high side LED current sense that enables the part to function as a “one wire current source;” one side of the LED string can be returned to ground anywhere, allowing a simpler one wire LED connection. Traditional LED drivers use a grounded resistor to sense LED current, requiring a 2-wire connection to the LED string.
The high switching frequency allows the use of tiny inductors and capacitors. A single pin performs both shutdown and accurate LED dimming control. Few external components are needed: open-LED protection and the Schottky diode are all contained inside a low proﬁle 3mm × 2mm DFN package.
- Tape and Reel: Add #TR
- Lead Free: Add #PBF
- Lead Free Tape and Reel: Add #TRPBF
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 1124 is an LED Driver with Integrated Schottky featuring the LT3591. The LT3591 is a fixed frequency step-up current mode DC/DC converter that drives up to ten white LEDs in series at 20mA. The input voltage range of the demo board is from 3V to 9V. 42V (typical) LED open circuit protection is provided.
The high side current sensing feature of the LT3591 allows “one wire” current source, i.e. the low side of the LED string can return to ground anywhere.
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:
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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:
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Sample & Buy
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.