I have a customer that is using an LMK04805 from National/TI. For their next gen product, they haven't finalized the baud rate, but depending upon what they choose, they would be interested in an LMK type chip with VCO rates of 2125MHz, 2200MHz or 2625MHz. The LMK04805 covers the VCO at 2200MHz, but the other two freqs fit into gaps that would be filled with LMK04804 and LMK04807.
I explained to them that ADI has a great alternative in the ADF4351 with a fundamental output frequency ranging from 2200 MHz to 4400 MHz. However, it also features the ability to divide-by-1/2/4/8/16/32/64 which will allow them to generate RF output frequencies as low as 35 MHz.
They have since reviewed the information I sent and responded with a series of questions. One feature that they are interested in is the low bandwidth loop filter. The LMK04800 family can provide a bandwidth as low as 10Hz, however, we couldn’t find this spec on this ADF4351 datasheet.
The customer believes that given the part does not have a dual loop architecture, it cannot can’t handle such a low bandwidth.
Can you verify the minimum loop bandwidth of the ADF4351?
Thanks in advance for your help.