Hi, everyone. I've been using STM32F030F4P6 for a project. While prototyping the circuit that I am going to use on my project, I shorted Vdda and Vdd pins together with 10uF and 100nF capacitors to the ground. I am giving exact 3.3V to these pins with an DC power supply.
The problem is my voltage readings are usually ±50mV off. My ADC configuration; continuous mode with software trigger with only EOC interrupt, SMPR set to highest (111). I've also used Vref to calibrate Vdda. Using Vref made results a bit better (Not that much). But it didn't make a lot of sense to me since Vref_int data was 1472 and Vref_cal was 1536. This tells me Vdda that I'm giving is 3.44V which is not true at all.
How can I improve this MCU's ADC? Should I seperate Vdda - Vdd and give a voltage reference to Vdda? Would these improve my readings that much?