Are there any suggestions for using Spread Spectrum Clocking with Nationals Channel Link devices?
Down Spectrum is best. Avoid center or up spectrum and carrier frequencies over 200 kHz are not recommended. PLLs tend to track in the 50 to 100kHz range. It is recommend to use smaller spread spectrum percentages – typically 1 and 2% are used while 3.5% borders on the higher side. On the higher side, the rate of change between PLL sampling positions may become too great and cause errors. Relevant Part: DS90CR217;DS90CR287;DS90CR213;DS90CR214;DS90CR215;DS90CR216;DS90CR217;DS90CR218;DS90CR283;DS90CR284;DS90CR285;DS90CR286;DS90CR287;DS90CR288;DS90CR481;DS90CR482;DS90CR484;DS90CR485;DS90CR486 Can Channel Link devices be used with Spread Spectrum Clocks? We do not provide test coverage for spread spectrum applications. However, Channel Link devices have been used by customers in spread spectrum clock applications without any tracking problems. Due to inherent PLL filtering effects, PLLs will help reduce the effect of spread spectrums — especially in the transmitter since the LVDS output c
