AnsweredAssumed Answered

ADF4351 analogue/digital lock detect

Question asked by TPiggin on Jun 12, 2012
Latest reply on Jun 25, 2012 by BobC

Hi, I think I am having trouble in getting my 4351 to lock. Initially I thought it was working, but when looking on a spectrum analyser I have a 1.6GHz spike as expected, but I have another spike of similar size offset by 6MHz, which suggests to me it might be hovering around the set-point and struggling to lock. This led me to look at the lock detect signals. Initially digital lock detect didnt work, but then I changed the LDP from 6ns to 10ns and got that to work on both the LD output pin and having the MUXOUT pin configured for digital lock. However, my issue is when changing the MUXOUT to analogue lock detect, which it never achieves. It always outputs a low on this pin. The datasheet does not really explain the difference between analogue and digital lock either. Hope someone can help.