After a suggestion from my previous question I'm planning to use this Photovoltaic isolated MOSFET gate driver to trigger a trigger input of this DAQ. It seems these devices do not require an auxiliary power supply. Below V1 is a 33Hz 0-5V pulse train input to the gate driver. Rtr is the input impedance of the trigger input of the DAQ where I guess it is at least 10Meg:
Digital input limitations of the DAQ is given as follows:
And here is the gate driver input current output voltage curve:
How can I size the input current hence R1 so that the trigger receives guarantee always between 1V to 5V input? The plot doesn't have much detail for 5V output.
The datasheet shows that the forward LED voltage drop is 1.4V at 5mA. In my case from Figure 3. it will be around 1.1V assuming I need 1mA input current.
So for 1mA R1 = (5V - 1.1V) / 1mA then R1 = 4k. But if I set the input current to 1mA; between 0 to 5mA Figure 1. curve is very steep which doesn't look stable. How can I size the resistor and current in that case for a more stable output around between 3V to 5V? A voltage divider at the output? I have no experience with this device.