PWM LM2596 buck converter?

Hi, e-bay is full of LM2596 based DC-DC converters. Like this one: http://www.ebay.com/itm/LM2596-DC-Step-Down-Adjustable-Converter-Power-Module-/280871420490?pt=LH_DefaultDomain_0&hash=item41653dc24a

Might be a simple question to some but is it ok to PWM their input or output?

I want to drive a few 10W LEDs and think of using converters to supply appropriate voltage for each color, but those on-board caps and advertised voltage reaction time make me think that it "will not blend"(c) with PWM..

How would you want to use PWM for the input ? You can do that on the output. Perhaps with an extra capacitor, but those modules can handle switching loads very well.

The LM2596 has an on/off pin, which you can use for the PWM signal. I know that has been done, you migh search www.hackaday.com for it. The LM2596 has an "start up" circuit according to the datasheet. I don't know how fast that is. Perhaps you can find it in the datasheet. Since those modules have a fixed frequency of 150kHz, a PWM signal of 100Hz for led's should be possible. But you have to try it to be sure.

Krodal:
The LM2596 has an on/off pin, which you can use for the PWM signal.

Thanks! Will see if I can try that :slight_smile:

I'm sorry for archaeology. Did someone made LM2596 voltage regulation via Arduino / ATmega? I'm looking for step down buck converter with voltage regulation via Arduino.

kivig found other solution for his problem and didn't make this.

Instead of potentiometer use analog output from aurdino.
0V = hight output voltage (depends of R1 and R2)
1,23 volt from aurdino = 0volt out

2596.jpg