I am using an EL357N optoisolator in a project and I am supplying it 5v through a 500 ohm resistor. It draws 7 milliamps. The absolute maximum rating for it is 50 milliamps. Do you think I am overdriving it and would it be better to lower the current? I understand this could affect the CTR but the output phototransistor is only driving the gate of a small mosfet at frequencies well below 1 hertz.