Solution Finder Get Tech Support

LED driver IC: sink current using PCA9685?

Posted by: Aubreyhu on 07/07/2021

Good day, all

New being here, I'm using a PCA9685 with a pinout board like Adafruit's. I'm trying to run a bunch of LEDs at 20 mA, and the chip is supposed to be able to source 10mA and sink 25mA. I understand that to have it Source, connect the LED between the PWM and GND pins and sink it between V+ and PWM. 

I've tried both ways and using a multimeter and a red LED I get 12.5mA. Why is it not 25 in Sink? Also, why do I get 12.5 on source mode as well?

Any idea of it? so if possible a simple explanation would be nice, thanks a lot.


Submitted by PI-Bombadil on 07/14/2021

Hi Aubrehu,


Unfortunately, PCA9685 is not a product of power integrations.