TNY278PN Driver CC CV

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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. 

One way would be to add an auxillary secondary winding and output stage to bias op amp