ADPD1080 How to calculate Intensity value ?

This is related to CN0409. Reference circuits are supported in a separate group. Please post it to:

https://ez.analog.com/circuits_from_the_lab/

@git Yoleri Thank you so much ! I post my questions at here: https://ez.analog.com/circuits_from_the_lab/f/q-a/533719/cn0409-calculate-the-level-of-water-turbidity

Hi

Thank for your support !

I also post my questions at this link:

https://ez.analog.com/circuits_from_the_lab/f/q-a/533719/cn0409-calculate-the-level-of-water-turbidity

Hi Lee,

By intensity are you referring to the light sampled by the photodetectors? The ADPD1080 measures the current signal (photocurrent) from the photodiode. Photodiodes generally have different wavelength characteristics but you should be able to get the illuminance (usually measured in lux or lx) from the photocurrent using the characteristics plot in the datasheet.

You can compute the photocurrent from the ADC code using the settings you have for the TIA. For example in TIA ADC mode (bandpass filter and integrator are skipped in this mode), table 29 of the datasheet shows that the TIA ADC resolution using a 25k feedback resistor is 2.92nA/LSB

Regards,

Nikko

why I config the current as the table，the ADC value gap vary much？