This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ADC128S102: How to Avoid or rectify effect of signal coming on one channel to the next channel i.e. cross talk of the ADC channel

Part Number: ADC128S102

Hello,

Here i am facing problem of signal cross talk between ADC128 consecutive channels,

so when i apply some high Voltage say 5 V on 1st channel of ADC and 0 V on 2nd channel of ADC and rest of the ADC Channels are also on 0 V , and i send instruction to read all 8 channel of ADC so i get result as, 

1st channel = 4095

2nd channel = 18 #problem is here i should get 0 digital reading here because i applied 0 V on this channel

3rd channel = 0

4th  channel = 0 and so on all 0 digital reading till 8 channel,

and this problem is constantly repeating and also when i apply high voltage on other channel say 3rd channel and all other channels are grounded so i see the high voltage effect of 3rd channel on 4th channel,

So basically when i apply high voltage on a channel of ADC it is effecting the Next channel so i need a solution on how to avoid or rectify this problem ?

  • Hello,
    The device has a spec of 82dB attenuation in channel to channel isolation, what you are seeing is a bit high. The most likely culprit for this is board layout. Is this test done on a fabricated PCB board? The input connections should be the furthest from each other for as long possible before coming closer to connect to the input pins of the device. Also, what is your input circuitry are there any modulating elements at the power supplies or near the input signals. If you would like, we can review schematic and layout

    Regards
    Cynthia
  • Hi Priyanka!

    Any feedback here? As Cynthia pointed out, layout is often an issue. Are you using any sort of drive amplifier ahead of the ADC128S102?

  • Hello Tom and Cynthia,

    Yes problem was with handmade soldered Circuit, now we are using pcb printed board , now the problem is resolved and for handmade circuit i used software solution to reduce ghosting effect.

    Thank you for pointing out the problem.