Dumb question, but that's my specialty, are you using a TCXO for the reference on the frequency generator chip?
-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
BinaryRock
- Thread starter brandon7861
- Start date
It was a regular crystal, one that I've had in stock for a while now and wanted to get used up.
Up until now, I had no idea TCXO's were even available in 2mm x 2.5mm packages, but, you made me look and now I have a choice to make (whether to add $3 more in parts per board or not). I might reconfigure the pads to accommodate both options and see how my crystal does first before ordering TCXOs.
Edit: Yea, I will do use TCXOs. .5ppm will have to be good enough because I am not spending more than a few bucks on the oscillator. And I am too poor to order the new micros and TCXOs in large quantity, I don't have thousands laying around to waste, so I will order small and only if they sell will I order more. Probably smarter that way anyhow.
Up until now, I had no idea TCXO's were even available in 2mm x 2.5mm packages, but, you made me look and now I have a choice to make (whether to add $3 more in parts per board or not). I might reconfigure the pads to accommodate both options and see how my crystal does first before ordering TCXOs.
Edit: Yea, I will do use TCXOs. .5ppm will have to be good enough because I am not spending more than a few bucks on the oscillator. And I am too poor to order the new micros and TCXOs in large quantity, I don't have thousands laying around to waste, so I will order small and only if they sell will I order more. Probably smarter that way anyhow.
Last edited:
Sorry, thought you already knew about those. I was thinking about putting one of those, an Si5153C, and an Atmel micro on a board for a DSS with an FM option.
Well, once I finally sell the old house and get some capital to invest. Which is a whole different rant.
Well, once I finally sell the old house and get some capital to invest. Which is a whole different rant.
Yea, for some reason I had it in my mind that these hadn't shrunk down like everything else. Since I now have a bunch of regular crystals, I wanted the option to use both. I added a separate set of pads for the TCXO, and when it is used instead of the normal crystal, a capacitor on the crystal pads will pass the TCXO output to XA (datasheet calls for a capacitor with external clock anyhow).
I think for AM a regular crystal is more than enough and I like the idea of being able to offer both options. The TCXO I chose is 0.5ppm and the original crystal I bought was 10ppm. I know 10ppm sounds like a lot, but considering most people will not be operating it at -20°C or at 70°C, I think its fine (and so does AI, but I welcome experienced opinions). If I make the assumption the ppm will only be 60 over a 20°C span, then I can calibrate it at room temp and AM users will never notice.
I am still going to wait for v1 to arrive to ensure there are no other issues hiding somewhere. I need to verify my mosfet buffer idea before ordering these black ones, but the file is in my cart ready and waiting.