#### black_rider

##### Newbie level 4

**must known circuits**

For example I give pdf links to some multichanel optocouplerhttps://www.vishay.com/docs/83646/83646.pdf and some darlington transisor array https://www.farnell.com/datasheets/7944.pdf

Now on datasheet there are a lot of data but what do I need to know?

For optocoupler input I assume that I need to know max current through photodiode and its resistance so I can calculate the needed resistance for a resistor that I need to add (input will be 12V). For the output I assume I need to know max continous collector-emitter current and voltage, so I know how high voltage I can bring to collector and how much current will be drawn through collector emitter.

What about darlington array. I assume that I need to know max continuos collector-emitter current and voltage. Do I need to know max base current voltage?

Can someone also write down the numbers since I am not able to get them from the datasheet.