Hi,
Thank you so much for your interest in our products and for using our community.
The switching frequency limitation on the FTM depends of the source that is clocking the module. It can be the system clock, the fixed frequency clock, or an external clock.
For the system clock you can consult in Table 5-1. Clock Summary of reference manual. For the fixed frequency, it must not exceed 1/2 of the system clock frequency. And for the external clock source, it must not exceed 1/4 of the system clock frequency.
Now the FTM outputs an square PWM signal, not sinusoidal. For that you need to focus in setting the correct external circuit to archive it based in the PWM frequency.
Hope it helps you.
Have a nice day!