it is very easy for this por ,you need some digital ckt is ok ,no need for the comparator from the point of current comsuption ! and maybe your trigger precision is between 100--50mV
first thing is comparator and canb designed with low power consumption thats not a problem. Hyaterisis ll be around 50-20mv based on ur application. Ur trigger pt=1.3 so u can use nmos diffpair at input. U didnt mentioned del time in ur spec?