Hello
I am using
NUCLEO-G474RE board to sample voltages from the the Battery management board. In the PCB board, I have opamp voltage divider to step down voltages around 24Volts to 2.5V level to be read from the STM. Please refer to the voltage divider network below. I have the divider node feeding into ADC. At node A, I am not seeing fluctuations, but at node B(Nucleo board side) I see the 400mV fluctuations. Please see the attached graphs. My setting are 96MHz clock prescaler divided by 10, sampling time is 42.5cycles, and buffer size is 4000. Grounds are connected by jumper wires with IDC connector and adc pins are connected by IDC+Jumper wires. I am not sure how this can be fixed. I tried slowing down the clock by increasing the pre-scaler number, but this didn't help. Could this be the ground bouncing case? I have been debugging this for weeks, and I have no clue what this is caused by.
Thank. you very much in advance
