High Input Voltage Comparator (Urgent)

[sofia_huze]

high-voltage comparator

I need to design a high input voltage comparator. input voltages are greather than 20v. I tried to give this input diff pair, but gate oxide breaks down (after vgs>7V).

can anyone send me papers or schematic.

helped one will be donated 100pts.

thanks,

sofia

 

[erikl]

I need to design a high input voltage comparator. input voltages are greather than 20v. I tried to give this input diff pair, but gate oxide breaks down (after vgs>7V).

You either need to use a High Voltage process, or you have to down-devide your input voltage externally, or by internal poly resistors, if the Design Rules allow for this.