As far as I know, TM4C123 LaunchPad safely accepts voltages values up to 3.3V . I got a CNY70 reflective optical sensor and want to connect it to one of the analog input ports safely as in the attachment. (each of +5V comes from 5V AC to DC adapter)
The main problem is that I don't understand much from the CNY70's datasheet. (I couldn't find anything about the ON state resistance of the transistor, which could make things much easier for me)
Could you please explain what calculations should I do, or which figures should I check in the data sheet in order to calculate the X resistance value for safe operation.
P.S: Please keep in mind that, I'm quite a newbie in electronics