Hi, I am working on a 12 channel LED lighting project using the FemtoBuck LED drivers.
Each channel is meant to limit current to a pre-set value, and we have a multitude of very expensive LEDs we do not wish to damage through incorrect use.
However, during the Arduino reboot, some of the channels go to full power output (330mA) for a few seconds. This is likely to kill our LEDs. is There any way to improve the function of these, so they dont switch to max power if PWM is interrupted, or is it going to require switching the power externally only after PWM is active?
Sounds like you are controlling a FemtoBuck via an arduino. When I did that for a project of mine, I believe I had a similar issue (LEDs briefly coming on during reboot). Looking at my schematic, it looks like I fixed that by connecting a 1k pull down resister to the FemtoBuck’s CTRL pin.
Reviving this.
I have two femtobucks controlling one led each and powered externally by a 7v battery. When power is connected, the leds turn on and only until the MCU boots and runs its code are they turned off and wait for their signal.
Would adding the 1k pulldown resistor to CTRL prevent them from turning on when power is supplied?
Yes, pulling CTRL low will disable the output.
Thanks! Where did you get that from for my reference?
Nevermind…totally missed it on the data sheet before…
