chaojixin wrote on Jun 4th, 2012, 8:41pm:both drawing is correct. the curve in original drawing is made by setting W/L of M3 larger than M6 , and the newer one (ordinary case which has real hysteresis) is made by setting W/L of M3 smaller than M6.
my question is, does the comparator in original drawing has any drawback?
It is only the inpput stage to a comparator.
You will probably need a second gain stage and an output buffer