I am analyzing a circuit which uses an Micro-controller to measure analog signals rms in digital form. There is one connection of circuit that i am not sure what it does.
See the Figure. Here Vref of MCU is connected to ground via two parallel capacitors. This micro-controller is chinese made so its datasheet is avaiable but not very detailed. Data sheet shows that Vref is internally connected to VDD/VCC which is 3.3V. Though i am not sure because i think it should be zero, because it compares input analog signal to detect its +ve and -ve cycle.
what would be the functions of capacitors if Vref is internally at VDD/VCC??
What would be the functions of capacitors if Vref is an Input Pin and it is grounded via these capacitors??