We are using part to sweep through 500 frequencies continuously. We are letting the device handle calibration at each freq without any assist. We read back lock status via SPI. Sometimes it fails to lock. The failure is always when we go from 2671.5MHz to 2684.5MHz. This happens to be the freq where device goes from VCO4 to VCO5.
We have checked and rechecked clocks, power etc. When it is in this unlocked state we can read back all correct values in its registers. Writing R0 a second time does succeed. Is this a known issue?