cancel
Showing results for 
Search instead for 
Did you mean: 

Why is there a pulse on ADC input channel

WSuke.1
Associate

I use ADC0 and ADC1 of STM32F334,I put a resistor of 1K between amplifier and ADC channel, configuring every IO setting by using CubeMX, but I find something strange, there is a pulse on ADC input pin,while amplier output is flat. And the result reading from ADC is about 0.5 V above its actual voltage, which is exactly the pulse voltage,when the input voltage goes high, the ADC pin pulse goes high,but it seems that there is always 0.5 V high. it can be seen from the image below, yellow is ADC0, blue is ADC1.ADC1 pulse is later than ADC0. Why is this happening ,how to solve it


_legacyfs_online_stmicro_images_0693W00000bkoP6QAI.png

1 REPLY 1
S.Ma
Principal

First check the nearby pins in case of cross talk.

Then change the sample and hold to be very big, does the pulse lenght change?