trigger de schmitt 200mhz

How to drive 200MHz sine wave to make it become square wave?
And guarantee this square wave to be loaded 5p capacitance at its output ?
Could anyone help me?

not clear at what level you are asking. If it is within the IC, then you may use schmitt trigger kind of circuit to convert to sq wave and drive using a driver

Yes, its in IC, 3.3v, swing full scaler.
but if use schmitt, after schmitt'output loaded 5p, the sq wave look like poor.