AnsweredAssumed Answered

How  to test the ADC input is not connected

Question asked by 燕琳 赵 on Feb 12, 2020
Latest reply on Feb 14, 2020 by Daniel Martynek

Dear expert,

I use S32K144, The ADC result is gotten with DMA interrupt. There is a problem about ADC, Could you help me ?

I found, When I disconnected the ADC1_SE0, which means the ADC annalog input is nothing, but I still can get the DMA interrupt, and the Digital output is nearly 5V. By the way, Vref_h = 5V, Vref_L = grand.

1.How can I know the ADC input is open circuit?

2.When a pin is not used as GPIO, the pull down can not be set. 

Thank you very much!