LMX2592: Frequency Drift

Part Number: LMX2592

LMX2592 frequency drifts from 8490MHz to 8510MHz after "one second". Other boards are okay. Hoping to get a quick fix on boards already in production line. Nothing fancy on implementation, just used eval board scheme except for a 4th-order loop filter. Thanks!

  • Hi Randy,

    I bet the VCO is still locking as the VCO drift is only 10MHz. this kind of small drift is usually due to reference clock drift or leakage in the loop filter. 

    BTW, after the frequency drift happen, if you program R0 one more time, will that fix the issue?

  • Hi Noel,

    Thanks much for your input. I'll try reprogramming R0 to see if this fixes the the problem. These are mass produced boards and I'll pull out the offending boards to examine their loop filters.