I present to you an LM3404 based high-power RGB-LED controller that can drive a single 100W RGB-LED chip. Two on-board voltage regulators can supply +5V and +12V for an external microcontroller and cooling fan, respectively. The BOM file contains untested part list for driving less powerful RGB-LEDs (3W-10W-20W-30W-50W) but I only sell the 100W version for now.

Current hardware version: V1.31

Features

• Power input: 36VDC @ 4A
• Reverse polarity protection on power input connector
• Forward voltage on each channel: 22 ‒ 34V (automatically adjusted)
• Forward current on each channel: 0.9A (set by a resistor)
• Enable/disable LM3404 drivers
• PWM color dimming on each channel
• +5V power supply for external microcontroller
• +12V power supply for cooling fan
• Selectable fan configuration (2/3/4-pin)
• PWM fan control
• RPM signal output from fan (3/4-pin only)
• LM35 temperature sensor connectivity
• Can be controlled with any PWM-capable 5V/3.3V microcontroller (Arduino / Raspberry Pi / ESP32)

Connector description

• Power input (J1): reverse polarity protected screw terminal
• LED red-channel output (J2): screw terminal
• LED green-channel output (J3): screw terminal
• LED blue-channel output (J4): screw terminal
• Cooling fan output (J5): standard +12V 3/4-pin fan connector
  • -: ground
  • +: +12V
  • S: sense (RPM)
  • C: control (PWM)
• Fan pin-selector (J6): a jumper here routes the F-PWM signal
  • 4P & x: 4-pin fan
  • 2P/3P & x: 2/3-pin fan
• +5V output (J7): standard 2.54 mm pin header to power external microcontroller
• Control pins (J8): standard 2.54 mm pin header
  • EN: pull this pin low to enable all LM3404 drivers or use a jumper to connect with the ground pin above it
  • RED: logic level PWM-signal (3.3V or 5V) to the red-channel
  • GREEN: logic level PWM-signal (3.3V or 5V) to the green-channel
  • BLUE: logic level PWM-signal (3.3V or 5V) to the blue-channel
  • F-PWM: logic level PWM-signal (3.3V or 5V) to the cooling fan for RPM control, no signal here means 100% RPM
  • F-RPM: fan RPM feedback (5V logic, not safe for 3.3V devices, two pulses per rotation, 3/4-pin fans only)
  • TEMP: analog signal routed from J9 (3.3V safe)
• LM35 temperature sensor (J9): if you want to measure heat sink temperature
  • + : +5V
  • T : analog signal (0 ‒ 1V)
  • ‒ : ground

Operation

• Don't hotswap on the J1-J4 connectors! Power down the system before you connect/disconnect high-current wires.
• Pull EN pin low externally or put a jumper on it to enable all LM3404 drivers. This pin is a simple ON/OFF switch, don't PWM it!
• Apply logic level PWM signal (3.3V or 5V, 100-2000 Hz) to RED, GREEN and BLUE pins to display colors and change brightness. If no control signal is present the RGB-LED won't turn on.
• Apply logic level PWM signal (3.3V or 5V, 100-2000 Hz) to F-PWM pin to control the cooling fan RPM. Leave this pin disconnected if you want 100% RPM by default. Make sure to put the jumper in the right place on the J6 connector!
• Read F-RPM pin to verify cooling fan RPM. This only works with 3/4-pin fans. Leave this pin disconnected if not used. This signal is NOT 3.3V safe (two 5V pulses every rotation).
• Read TEMP pin to get LM35 temperature sensor analog value (ideally mounted on the heat sink). Voltage/temperature conversion: 0mV = 0°C, 250mV = 25°C, 618mV = 61.8°C (10mV/°C). Leave this pin disconnected if not used. The analog signal is 3.3V safe (0-1V).

Recommended power supply

Mean Well LRS-150-36 150W/36V/0-4,3A or equivalent.

Compatible 100W RGB-LED

• Forward voltage:
  • red: 22 ‒ 26V
  • green: 33 ‒ 37V
  • blue: 33 ‒ 37V
• Forward current: 0.9A / color

Alternatively you can use single color 30W LEDs per channel that have roughly the same forward voltages and exactly 0.9A forward current.

Package content

1x High-Power RGB-LED Driver V1.31 board (fully assembled and tested or PCB only)

Weight

65 grams

RGB-LED, heat sink, PSU and microctontroller is not included! For further information and details check the documentation!