Do you have an idea if this is inherent to buck-converters, or due to the small size of the components on these boards? When I build a buck-converter from bare components, each component is much larger than on those boards. Only the coil is already near the size of such all-in-one boards. Just wondering what impact the size of the components have on the HF noise.karrika wrote: ↑Fri Mar 06, 2020 11:37 amThese buck converters look very familiar.
There is one problem in using them. They create a lot of high frequency noise on the 5V power line. I have never been able to use these converter with the 7" official touch screen. The display image looks ok. But the touch screen part refuses to work. Adding extra filtering after the converter does not help either.
I have tried these with multiple Pi's and multiple 7" Official screens.
In any case I rather use the official PSU as it produces clean power.
I mentioned the blue HDMILTolledo wrote:
Good to know.drgeoff wrote: ↑Sun Jul 19, 2020 4:34 pmIt is well known that SMD electrolytics like those in the buck converter boards in LTolledo's photos are extremely prone to failure. Loss of capacitance and increased ESR. They are not suitable for the level of ripple current encountered in switch mode converters delivering the current that RPis require. Expect problems sooner or later with such modules.
drgeoff wrote: It is well known that SMD electrolytics like those in the buck converter boards.....
if it does happen, I can replace those with standard (non SMD) Rubicon 105 types.hary wrote: can we fix them by replacing the failling capacitor with a proper one ?
If yes, which one should we choose ?
Out of several dozen LM2596 type like LTolledo's used personally and many more used by others about 10% failed with Pi3 and Pi4. In a few cases they just didn't seem to provide enough current but in others it was that cap falling or knocked off. Less than 1% fail with XL4015 type for only a few pennies more.hary wrote: ↑Sun Jul 19, 2020 8:51 pmBut LTolledo didn't seem to face such problem anytime !
As these small buck converter are very usefull, can we fix them by replacing the failling capacitor with a proper one ? If yes, which one should we choose ?
At 10pcs, why don’t you make your own PCB layout and order it assembled?hary wrote: ↑Thu Sep 03, 2020 6:53 pmReading this thread, I've ordered 10 MP1584EN buck converter for different project including RPi4.
It seems to work ok with the RP64 as desktop, but they hardly handle more than 1.5-1.6A max instead of the 3A advertised !
At more amp than 1.6A, I think they become too hot and the security comes into action !
Plus adjusting the right voltage output is quite of a chalenge with the kind of potentiometer they have !
Sorry, was reading this thread on the go and thought it’s topic starter getting more and more converters instead of building own custom. Just wondering how much additional effort spent to fit those in place.
I know it will become hot as current draw increases.... thus the heatsink on the chip and on the inductor.hary wrote: I think they become too hot....
it is quite a challenge, requires precise movement from my shaky handshary wrote: Plus adjusting the right voltage output is quite of a challenge with the kind of potentiometer they have