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Posts: 1
Registered: ‎12-10-2015

SI5338: Can't create four 500kHz clocks with phase of 0, 90deg, 180deg, 270deg.. help needed.

Hi,

 

Learned today that the SI5338, otherwise a powerful, flexible 4-chan synth, doesn't seem to allow outputs to be phased predictably, if the divisor R is greater than 1.  Using this to try and create four 500kHz clocks, which is a very low frequency relative to f_vco, thus requiring R>1.  In our app, it's important that we stagger the four outputs in phase.  We're playing with the registers now, but looking for help.

 

Thanks!

 

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Posts: 27
Registered: ‎06-16-2014

Re: SI5338: Can't create four 500kHz clocks with phase of 0, 90deg, 180deg, 270deg.. help needed.

A few questions to help answer your question:

1. What are your requirements for these 4 clocks with respect to edge to edge timing? In other words how accurate do you need the 90 degree phasing?

2. Do you have a local MCU or equivalent that could configure/set the Si5338 in real-time? (mainly at start-up)

Thanks