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WSuke.1
Visitor II
May 25, 2023
Question

Why is there a pulse on ADC input channel

  • May 25, 2023
  • 1 reply
  • 853 views

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

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1 reply

S.Ma
Principal
May 25, 2023

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?