Hi Lincoln,
On 12/10/2014 03:49 AM, Dave M wrote:
lincoln wrote:
Hello,
I'm having a dumb idea, I have an MCU that uses a 20 MHz VC-TCXO. The
micro, among other things, runs a loop and correct the oscillator by
using a 1pps from a gps. I have a 10 MHz mv200 that I would like to
try to use. I've got the control voltage handled but i will need to
multiply its output up to 20 MHz. What would be the most kosher way
do do this? I was having a look at Cypress's CY22381 because I have
the programmer but the chips are not widely distributed. But nether
are mv200's Silicon labs also make all kinds of clock chips as well.
What do you guys think? What would be the best way to scale up by X
2? lowish phase noise / jitter is important, low power is not.
Thank you,
Lincoln
A couple ways to go on a doubler.
Minicircuits makes a line of frequency doublers, such as the SK-2, RK-2,
RK-3, etc. You could also roll your own using a balun and a diode
bridge (http://www.techlib.com/files/diodedbl.pdf). Insertion loss is
pretty hefty in both solutions, so you''ll need to follow with a 10-15db
amp.
As you is then going to use it for digital circuits, don't forget to
square it up using a gainstage, look at the Wenzel sine-2-square, or the
input stage of TADD-2 (which is the Wenzel design), and then run it
through a pair of inverters before it his the MCU.
If you already have a VC-TCXO, then you could divide it down to 10 MHz,
then use a digital phase comparator and a PI-integrator (2 resistors, 1
capacitor and an op-amp) to create the EFC for the VC-TCXO.
Cheers,
Magnus
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