OptoIsolated_RS232.pdf
Hello,
I have been using an opto-isolated setup as seen in the PDF above in an ATE to interface between a Raspberry Pi and the unit under test. Initially the setup was working fine and 400+ boards were tested successfully, however suddenly the ATE started failing, and certain components on the unit under test would warm up to a concerning temperature, leading me to believe a component was damaged leading to high current draw. An analysis was done with a scope and no comms signals were relayed to the output of the opto-isolators, the. The current draw of both after they stopped working was 50mA. I replaced the 2 opto-isolators and the buffer, and added a TVS component to protect against static, the ATE functioned as intended for a while then the same issue showed up again. I have went through the opto-isolation setup again and I believe that my setup correctly matches it, I redid the Rs resistor calculations and I believe I am using the correct ones for this setup. I cannot figure out why the components keep getting damaged. Any help or insight would be greatly appreciated
I see you submitted this same issue through our online technical support system, Ticket 389186, which I already responded to. I will continue to support you through our online technical support system.
Best regards, Cindy, Online Applications Engineer
Thank you Cindy, I thought no harm in submitting in both. More chance someone that can help comes across it.