I want to drive a H11L1 Opto.My line voltage is 220v 50Hz,I want to calculate series resistor.The opto must be turned off 500 us before zero so i calculate the voltage at that time [ V1 = 48v],The minimum current to drive emitter is 1 mA so calculate the resisto [R1 = 47 KΩ].

now is turn to check the Absolute Maximum values :

1.Maximum forward current is (311-1) / 47k = 6.5 mA(ok).

2.LED power dissipation is less than 10 mW(ok).

But i don't know how to calculate the reverse voltage. Please help me to calculate it.

Thanks.