There are two factors to that. Cross conduction is one, the other is the current pulse needed to charge the capacitance of the switched signal (the trace capaci

There are two factors to that. Cross conduction is one, the other is the current pulse needed to charge the capacitance of the switched signal (the trace capacitance but also the gate capacitance of the next stage(s); of course this simple model is only an idealized concept with current process nodes).