The
tools automatically configure the simulation to
meet the input and output frequency requirements
given, and make assumptions about other parameters
to give some default simulations. However, the
user may chose to make adjustments for more
accurate simulations to their application. For
example:
- Entering the VCO Gain of the external VCXO or
possible external VCO used device.
- Adjust the charge pump current to help with loop
filter component selection. Lower charge pump currents result in smaller components but
may increase impacts of leakage and at the lowest values reduce PLL phase noise
performance.
- Clock Architect allows loading a custom phase
noise plot for reference or VCXO block. Typically,
a custom phase noise plot is entered for CLKin to
match the reference phase noise to device; a phase
noise plot for the VCXO can additionally be
provided to match the performance of VCXO used.
For improved accuracy in simulation and optimum
loop filter design, be sure to load these custom
noise profiles for use in application.
- The PLLatinumâ„¢ Simulation tool can also be
used to design and simulate a loop filter.