Hi there. I would like to have an external reference clock to multiple LimeSDR’s. Can this be done by daisy chaining them? i do no want the “clock out” of them to reference their internal clock, but instead the external reference. Basically i want each SDR in the chain to use and pass through the original external clock. Can that be done? maybe disabling the internal clock? Here is a pic of the options that exist. I’d like to implement option 1 in the same way option 2 functions. Thanks.
With the LimeSDR USB, there is a clock in & a clock out. I am just guessing that is just what you want.
You can configure it for internal or external clock.
Ed
Can this be done by daisy chaining them?
Yes*
I (…) want the “clock out” (…) to reference (…) the external reference.
The frequency will be exactly the same and the phase will have a slight constant offset. And that would be the same for all SDR’s that I know in that particular configuration (1).
ref: Page 3 of the schematic gives the block diagram for the clocks.
If I’m totally honest I can’t see any way of getting 1 and 2 in your diagrams to be equivalent with any SDR using a clock in+out that I know. All of them have some form of clock buffer and that will change the phase slightly from device to device but by a constant amount. Even the cable will adjust the phase by a small amount.
- If you look at page 14 of the schematic, R151 is Not Fitted by default, so you need to add a 0R resistor to enable REF CLK OUT (ref: About the clock output of limesdr - #7 by Zack )
Thanks very much for the input. It looks like there is no real way to bypass the internal clock at the output. I guess i will just stick with the 2nd implementation for now. Thanks again.