Hi, i wish to use an  opamp for a CC CV design using TNY278PN. output 36V/350mA.

since the max. supply voltage for an opamp is 32-36V, whats the best way to keep the voltage to the opamp within safe limits? would a zener diode be enough? for lower output voltage, i have supplied the opamp directly from the output thru a resistor.

since the o/p of the opamp is limited by its supply voltage, if i reduce the supply voltage to say 26V, then the output of the driver also drops to 28V from 36V. 

i also want to design for output of 48V. so how do i limit the supply voltage to the opamp without affecting the output?   

 Please advise.

Thanks.