Over and undervolatge PMOS switch

[khaylenag]

I used the attached circuit for over and under voltage cutoff. I found out that the PMOS damaged when I slowly reduce the input voltage close to 9V. Any idea why this happen?

 

[BABESH]

FROM INITIAL analysis of u r sch, i found that
at 9v i/p the zener current supplied is around 15uAmp, which probably may not be sufficient to maintain the zener voltage, so try maintain the same resistor ratio and reduce the resistor values 4.7K and 75K


--Babesh..