We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
I use 89C51ED2 (44 pin PLCC) in my circuit and I am facing a peculiar problem. The reset circuit of micro-controller consists of 8.2K and 10uF capacitor. When powered on the reset pin (PIN 10) remains in HIGH state, even though it is pulled down to ground by 8.2K resistor. I checked that RESET pin is not shorted to VCC. This problem persists only in a few PCBs and rest of the PCBs works fine. I have used identical components in all PCBs. But when I remove the micro controller, PIN 10 of IC base comes to LOW state. What can be the reason for this problem? Thanks in advance.