Choosing by pass and decoupling capacitor for an optocoupler

Hi all,

I am trying to figure out the size or capacitance value for the following chip ( IL- 715 ),

I know that I can use the following formula to find the capacitor

C = ( I x N x t ) / V

Where, C = Capacitance I = Current needed to switch output from low to high N = number of outputs t = time required for the capacitor to charge V = allowable voltage drop in Vcc.

The problem is that I can not find the current needed to switch output from low to high and also the drop in Vcc in the data sheet. Can any body give some suggestions!! Is there another practical method to calculate capacitance value?

I am planning to use all four channels of the IL-715. The signals are

Regards,

John