I am using OPA380 for transimpedence amplifier with 3.3M feedback resistor and not feedback capacitance. Can Any one tell me the amount of light falling on photodiode in Watts if the output voltage swing is from 0 to 2V ?
I presume, you can calculate the photo curent as Id = 2V/3.3M (applying ohms law). To know the radiation power, you'll refer to the photo diode data sheet.