The FemtoBuck is a compact, single-channel constant-current LED driver capable of driving high-power LEDs at up to 350 mA with input voltages up to 36 V. Dimming is controlled via PWM or an analog signal (0–2.5 V), and the driver achieves approximately 95% efficiency across its operating range.

Based on the AL8805 driver IC, the FemtoBuck features dual power input and dimming control pins, a footprint for a 3.5 mm screw terminal, and zip-tie anchor points for securing wires. A solder jumper on the board can be closed to double the output current from 330 mA to 660 mA.

Key Features

• Constant Current Output – 330 mA default, 660 mA with solder jumper
• Wide Input Voltage – Up to 36 V
• ~95% Efficiency – Minimal heat generation
• PWM or Analog Dimming – 0–2.5 V analog or PWM input
• Compact Design – Small footprint with screw terminal option
• Zip-Tie Anchors – Secure wires to the board after soldering

Specifications

• Driver IC – AL8805W5
• Output Current – 330 mA (660 mA with solder jumper)
• Input Voltage – Up to 36 V
• Dimming Control – PWM or 0–2.5 V analog
• Efficiency – ~95%
• Channels – 1

Resources

• Hookup Guide
• AL8805 Datasheet (PDF)
• Schematic (PDF)
• Design Files (GitHub)