PCA9685 doubt about led

Using Arduino LEDs and Multiplexing
#1

I have some questions / doubts on the PCA9685 that I want to use to drive groups of LEDs 0603 (2.9V 20mA) in parallel of variable number on each output (an output with 2, another with 13 LEDs in parallel, etc ..) , I thought about this card because I'm about thirty different releases on which I want to make independent fades, if there are other solutions you can propose as well: 1. If I have not misunderstood every single output leads to max 25mA, right? So I can directly connect (with due resistance) only 1 or 2 leds at most? 2. All the outputs have a resistance in series of 220ohm, but in theory for a LED would be enough for 100ohm, how can I do? I remove the resistance from the circuit? 3. I imagine therefore that if I want to pilot the 13 LEDs in parallel must use a logical mosfet, is the IRL540N OK? Are there any other solutions besides using mosfets? Is it correct to say that 20mA x 13 leds = 260mA will pass? 4. Since I am using the LED wire (0.1mm copper) for connections with 13 LEDs it overheats? too much current?

Thanks

#2

So I can directly connect (with due resistance) only 1 or 2 leds at most?

Yes.

All the outputs have a resistance in series of 220ohm

No they don’t.

I imagine therefore that if I want to pilot the 13 LEDs in parallel must use a logical mosfet, is the IRL540N OK?

Yes. Use Figure 13 in the data sheet, each LED should have its own series resistor.

Are there any other solutions besides using mosfets?

Yes you can use a transistor or a darling pair but you must include a base resistor.

Is it correct to say that 20mA x 13 leds = 260mA will pass?

Yes.

  1. Since I am using the LED wire (0.1mm copper) for connections with 13 LEDs it overheats? too much current?

No that should be fine.

#3

Thanks for your answers.

About the 220ohm resistance on output, here https://www.adafruit.com/product/815 they indicate "220 ohm series resistors on all the output lines to protect them, and to make driving LEDs trivial", but I guess you're referring to the chip while I was referring to the board, correct?

#4

Creas: I guess you're referring to the chip while I was referring to the board, correct?

Yes, you only mentioned the chip, you did not mention the board.

#5

I guess you're referring to the chip while I was referring to the board, correct?

Yes we can only go on what you actually say, tough but mind reading is a sixth level Jedi trait.

#6