Mean Well LDD-300L DC/DC Step-Down Converter, 9-56 VDC Input, 2-52 VDC Output, 300 mA, 15.6 W, PCB Mount

Lighting designers and electronics engineers integrating LED arrays into architectural fixtures or industrial machinery often need a compact, efficient current source that can handle a wide input range. The Mean Well LDD-300L DC/DC step-down converter delivers a constant 300 mA output from a 9–56 VDC input, making it ideal for powering LED strings from existing DC buses or battery systems. Its non-isolated buck topology achieves up to 96% efficiency, minimizing heat and maximizing reliability in space-constrained PCB designs.

Key specifications

• Input voltage range: 9–56 VDC
• Output current: 300 mA (constant current)
• Output voltage range: 2–52 VDC (compliance voltage)
• Maximum output power: 15.6 W
• Topology: Non-isolated step-down (buck)
• Dimming: External PWM control
• Remote ON/OFF function
• Efficiency: Up to 96%
• Protections: Short circuit, over temperature
• Operating temperature: -40 to +71 °C
• Mounting: Through hole (PCB mount)
• Cooling: Free air convection
• Compliance: UL, cUL, CE, ENEC
• MTBF: >1,800,000 hours

Why choose it

The LDD-300L belongs to Mean Well's LDD-L series, known for its high reliability and long service life. Its wide input voltage range allows use with various DC power sources, from 12 V batteries to 48 V telecom rails. The integrated PWM dimming input enables smooth brightness control without additional components, and the remote ON/OFF pin simplifies system power management. The converter's high efficiency reduces thermal stress, eliminating the need for forced cooling in most applications.

Ideal use cases

• LED lighting systems in commercial and residential spaces
• Industrial machine vision lighting
• Automotive and marine LED lighting (with appropriate DC supply)
• Portable and battery-powered LED devices
• Architectural accent lighting requiring PWM dimming

Good to know

This converter is a non-isolated design, meaning the output shares a common ground with the input. Always ensure proper insulation and safety measures when integrating into end products. The LDD-300L is supplied in a compact through-hole package, suitable for automated PCB assembly. For higher current requirements, consider other models in the LDD-L series, such as the LDD-350L or LDD-500L.