My customer had a question regarding the AD9371. and the evaluation boards that they had recently purchased. It remains unclear to us at this point what the limitations are on tuning speed of the on-chip VCO.
We would like to know what is the minimum time achievable for changing the frequency of the LO on the transceiver in the Rx and Tx stages from one band to another. For example, assume that we are using the full instantaneous bandwidth of the DAC on the Rx chain (100 MHz). If we have a carrier modulated at 500 MHz, how quickly can we re-tune the LO for a frequency of 550 MHz, 600 MHz, etc. ? I understand that there exists a feature for fast PLL re-tuning, but I am uncertain what this will imply for frequency stability, e.g. what the average lock/settling time is assuming some tolerance in frequency offset (say, within 1 MHz, 100 kHz, 10 kHz of target frequency, etc).