[time-nuts] Slightly OT: interest in a four-output, ultra-low jitter, synthesizer block?

John Ackermann N8UR jra at febo.com
Thu Jan 25 09:32:56 EST 2018

After the recent discussion about Silicon Labs clock generators, I 
looked at their Si5340A part and think it will be useful for a ham radio 
project I'm working on.  While it can do other things, for my use it 
would use a 10 MHz input clock and generate 4 independent outputs in the 
range of 100 kHz to 1028 MHz.  Its jitter is <100fs, which translates to 
"not bad" phase noise.  Here's the data sheet if you're interested:


The challenge is that the chip is a 7x7 mm 44-QFN package and really 
wants to be put on a six-layer circuit board.  That's doable, but 
challenging, for home assembly.

Rather than designing the chip into a larger circuit board, I'm thinking 
of doing a small "carrier" board that would include just the chip and 
critical bypass caps and have headers to plug into the main board. 
Then, you could just drop the carrier into a project-specific board and 
not have to worry about the complex layout and mounting.  I have a 
contract manufacturer who can build these up, if there's enough quantity 
to justify the setup cost.

If you'd be interested acquiring in one or more of these, please drop me 
a line off-list (jra at febo dot com).  I don't think this will be a 
TAPR project, but if there's enough interest to build 25 of these 
carriers, I can probably make that happen.  And remember -- this is just 
the chip; you'll need to provide the rest of the circuit.


More information about the time-nuts mailing list