"Ramp-up mode is used for a fast response on an increase of the output load. In this situation the average current through
the coil is too low to keep the output voltage at the required level. An extra long phase 1 is included to give a fast increase
of the average current through the coil. " 所以 固定T1不变 是不是不利于瞬态响应，，
https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=708161&tag=1 “Integrated DC/DC converter with digital controller”， 1998
基于这种reference window的方法 能够提高瞬态响应，，能不能把这个方法用给我们的delayline