Hello,

============ Context
I’m using simulink with external mode to pilot a launchpadXL F28379D and I use a lot of ADC readings.
ADC_C is used to measure 2 differencial inputs (C_IN2/IN3 and C_IN4/IN5) <=> These measurements present no issue
ADC_B is used to measure 4 single ended-inputs (B2, B3, B4 and B5)
ADC_A is used to measure 4 single ended-inputs (A2, A3, A4 and A5)
My outputs are DAC-A, DAC-B and ePWM 1,2 and 3.
I’ve shared a model for ease of debugging : "Launchpad_Instanciation.slx".

============ Measurements
For the measurements I have the board by itsef and a DC power supply to test the PINs.
To confirm the proper operation of the ADC I input a voltage between the concerned PIN (+) and the board’s GND (-). The issue appears when I test the measurements done with ADC_A and ADC_B. See "InterferenceBetweenADC.png".
In ADC_A
when I input a voltage in A2, I have a input reading. The issue is that I also have a small reading in A3
when I input a voltage in A3, I have a input reading. The issue is that I also have a small reading in A4
when I input a voltage in A4, I have a input reading. The issue is that I also have a small reading in A5
when I input a voltage in A5, I have a input reading. The issue is that I also have a small reading in A2
In ADC_B I have the same issue
when I input a voltage in B2, I have a input reading. The issue is that I also have a small reading in B3
when I input a voltage in B3, I have a input reading. The issue is that I also have a small reading in B4
when I input a voltage in B4, I have a input reading. The issue is that I also have a small reading in B5
when I input a voltage in B5, I have a input reading. The issue is that I also have a small reading in B2

============ Question
Why does an input voltage on a ADC’s input would impact the "next" input of the same ADC?

I appreciate the time you took to read my issue and any help will be greatly appreciated.
Kind regards,Hello,

============ Context
I’m using simulink with external mode to pilot a launchpadXL F28379D and I use a lot of ADC readings.
ADC_C is used to measure 2 differencial inputs (C_IN2/IN3 and C_IN4/IN5) <=> These measurements present no issue
ADC_B is used to measure 4 single ended-inputs (B2, B3, B4 and B5)
ADC_A is used to measure 4 single ended-inputs (A2, A3, A4 and A5)
My outputs are DAC-A, DAC-B and ePWM 1,2 and 3.
I’ve shared a model for ease of debugging : "Launchpad_Instanciation.slx".

============ Measurements
For the measurements I have the board by itsef and a DC power supply to test the PINs.
To confirm the proper operation of the ADC I input a voltage between the concerned PIN (+) and the board’s GND (-). The issue appears when I test the measurements done with ADC_A and ADC_B. See "InterferenceBetweenADC.png".
In ADC_A
when I input a voltage in A2, I have a input reading. The issue is that I also have a small reading in A3
when I input a voltage in A3, I have a input reading. The issue is that I also have a small reading in A4
when I input a voltage in A4, I have a input reading. The issue is that I also have a small reading in A5
when I input a voltage in A5, I have a input reading. The issue is that I also have a small reading in A2
In ADC_B I have the same issue
when I input a voltage in B2, I have a input reading. The issue is that I also have a small reading in B3
when I input a voltage in B3, I have a input reading. The issue is that I also have a small reading in B4
when I input a voltage in B4, I have a input reading. The issue is that I also have a small reading in B5
when I input a voltage in B5, I have a input reading. The issue is that I also have a small reading in B2

============ Question
Why does an input voltage on a ADC’s input would impact the "next" input of the same ADC?

I appreciate the time you took to read my issue and any help will be greatly appreciated.
Kind regards, Hello,

============ Context
I’m using simulink with external mode to pilot a launchpadXL F28379D and I use a lot of ADC readings.
ADC_C is used to measure 2 differencial inputs (C_IN2/IN3 and C_IN4/IN5) <=> These measurements present no issue
ADC_B is used to measure 4 single ended-inputs (B2, B3, B4 and B5)
ADC_A is used to measure 4 single ended-inputs (A2, A3, A4 and A5)
My outputs are DAC-A, DAC-B and ePWM 1,2 and 3.
I’ve shared a model for ease of debugging : "Launchpad_Instanciation.slx".

============ Measurements
For the measurements I have the board by itsef and a DC power supply to test the PINs.
To confirm the proper operation of the ADC I input a voltage between the concerned PIN (+) and the board’s GND (-). The issue appears when I test the measurements done with ADC_A and ADC_B. See "InterferenceBetweenADC.png".
In ADC_A
when I input a voltage in A2, I have a input reading. The issue is that I also have a small reading in A3
when I input a voltage in A3, I have a input reading. The issue is that I also have a small reading in A4
when I input a voltage in A4, I have a input reading. The issue is that I also have a small reading in A5
when I input a voltage in A5, I have a input reading. The issue is that I also have a small reading in A2
In ADC_B I have the same issue
when I input a voltage in B2, I have a input reading. The issue is that I also have a small reading in B3
when I input a voltage in B3, I have a input reading. The issue is that I also have a small reading in B4
when I input a voltage in B4, I have a input reading. The issue is that I also have a small reading in B5
when I input a voltage in B5, I have a input reading. The issue is that I also have a small reading in B2

============ Question
Why does an input voltage on a ADC’s input would impact the "next" input of the same ADC?

I appreciate the time you took to read my issue and any help will be greatly appreciated.
Kind regards, f28379d, interference, adc inputs MATLAB Answers — New Questions

​