Tool/software:
I designed a circuit using the TLC555IDR timer IC where a trigger pulse(from connector J301) switches its output high and it's output is connected to both an optocoupler and a GPIO(in a parallel sense). The optocoupler requires 5-7mA, but when connected, the output voltage drops to 1.6V, insufficient for the GPIO's high logic level. Removing the GPIO had no effect, but removing the optocoupler restored the output to 3.3V. According to the datasheet, the TLC555IDR can source up to 15mA. Could someone help clarify if my conclusion about the timer's current sourcing capability is correct?