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Hi
I m working on a circuit which need to drive an optocoupler(4n35) using a micro controller. The problem is when i connect the uc with the optocoupler the low logic pin of the controller rise upto say 2.26V. I have checked the datasheet of the at89s52(micro contoller i m using) it says the pin can sink a max of 10 mA so i added resistance of 330E on the emmiter side of the optocoupler. So, the net current sinked by the optocoupler is (4.80-1.18)/330=10.9mA.
4.98V= Vcc, 1.18V= Vf of optocoupler. But still the problem persists, anyone please let me know why this happens or how to drive optocoupler using microcontroller.
Thanx
I m working on a circuit which need to drive an optocoupler(4n35) using a micro controller. The problem is when i connect the uc with the optocoupler the low logic pin of the controller rise upto say 2.26V. I have checked the datasheet of the at89s52(micro contoller i m using) it says the pin can sink a max of 10 mA so i added resistance of 330E on the emmiter side of the optocoupler. So, the net current sinked by the optocoupler is (4.80-1.18)/330=10.9mA.
4.98V= Vcc, 1.18V= Vf of optocoupler. But still the problem persists, anyone please let me know why this happens or how to drive optocoupler using microcontroller.
Thanx