I have set up a ADPD103 Evaluation Board with two photodiodes (PD1 and PD2) and one LED. I want to measure the intensity of the LED with both photodiodes. When i bring the LED close to PD1, the signal rises to high LSBs, but at the same time the signal of PD2 decreases for a certain amount.
But when I disconnect PD2 from the Evaluation board, and bring the LED close to PD1, the signal of PD2 rises for a fraction of the signal of PD1.
This crosstalk gives me wrong results in my measurements. Is there a meaningfull reason for that, and does anyone have a solution to get rid of it?