Hi ,I used STM32F103ZET6 PIN28 PC2 ADC funtion to get the voltage of CMP_V. The voltage of this pin(PC2) is 0.032V when R335 is 100 K,CMP_V is olso disconnected from any circuit. I try to change the value of R335 to 68K, the voltage of this pin(PC2) is change to 0.022V. So I deciede to reduce the R335, the voltage of this pin(PC2) is decrease too .
Use a emitter follower to PIN PC2，may eliminate impact of this voltage;
Does any one meet this problem,and resolve it ? I guess there is a week leakage current inside the chip from this PIN PC2 for some reason that made by register configuration.