SNAU308A November 2024 – May 2025
Whenever the VCO frequency is change, a VCO calibration is required to select the right VCO core and band for the PLL to lock. In these LMX devices, there are 7 VCO cores and each core has 192 bands. Selection of the VCO core and band is done automatically whenever register R0 is programmed with FCAL_EN = 1. This is called No Assist operation. TICS Pro EVM default mode is setup for No Assist operation. If there is no requirement to the VCO switching time, using No Assist operation is recommended. However, if your application requires very fast VCO switching, these devices can be placed in Full Assist operation mode. In this case, VCO calibration is bypassed. See application note SNAA336 for VCO calibration details.