Si5351A waveform

[brandon7861]

Buy it from Adafruit, they said. The rest are counterfeit, they said.

Take a look at those harmonics jump around The phase noise is spectacular. Bottom one is a video

 

[brandon7861]

Wow, I just got a better look with my camera. Those top numbers sure seem different from the rest of the printing

I do have mouser ones, but I've never swapped a chip that small. Not sure how this will go, i definitely dont have the proper equipment to do this lol

 

[TM86]

I do have mouser ones, but I've never swapped a chip that small. Not sure how this will go, i definitely dont have the proper equipment to do this lol

For something that size hot air is usually recommended. So all you need to do is find a politician who's looking for contributions...

 

[brandon7861]

For something that size hot air is usually recommended. So all you need to do is find a politician who's looking for contributions...

Got the hot air, but I don't have that fancy beaded solder paste or cupped tips for drag soldering. Im going to give it a try anyhow. Dang pin header has to come out first though.

 

[brandon7861]

Got it switched, Not sure how the parts survived the excessive heating while I fumbled around getting it in the right spot, but it worked. That phase noise is gone now. It still has the harmonics as expected, but at least the frequency is stable.

 

[brandon7861]

It only took a couple lines of code to calibrate it and make it output. The one thing keeping me from playing with these turned out to be not that complicated. An LC filter to clean up the output and it should be usable to replace crystals.

The next thing is to figure out is how to get rid of the micro. Unfortunately, this thing needs to be told what to do at startup. Maybe an eeprom or something.

 

[nomadradio]

Or a RAMless AVR processor with eight pins. And a header socket to upload the frequency. Would be more compact.

73

 

[brandon7861]

Or a RAMless AVR processor with eight pins. And a header socket to upload the frequency. Would be more compact.

73

Ill have to learn how to use those, I am not good with microprocessors. No experience at all.

 

[brandon7861]

Or a RAMless AVR processor with eight pins. And a header socket to upload the frequency. Would be more compact.

73

You have any suggestions for a simple one I could start playing with?

 

[brandon7861]

I guess I have two things to learn. The little microcontroller and the chip communication, because without the arduino library someone else already has set up, I have no idea how to talk to that little clock generator. I guess the next step is to scope the SDA and SCL lines while I tell it something known, then try to make sense of the datasheet.

 

[nomadradio]

Or maybe an Arduino Pro Mini version is small enough?

73

 

[brandon7861]

Or maybe an Arduino Pro Mini version is small enough?

73

That certainly would simplify things. I need to order a few of those. Thanks!

 

[TM86]

If you need to go smaller than the Arduino pro-mini there's the "attiny" chips. At least some of those are programmable from the Arduino IDE.