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.

ADS8321: Sample Switch Reistance

Part Number: ADS8321

What is the sample switch on resistance in ADS8321?  Thx.

  • Hello Andy,

    I have reached out to the design team for this question. I will post the answer once I hear back.

    Thank you,
    Reed
  • Thanks Reed!!  Also, could you please confirm – this part’s sample switch only closes after (a) the /CS line goes low and (b) the DCLOCK train is started? So, the sample time window is a fixed # of DCLOCK cycles? (referencing Table I and Figure 6 in the datasheet).

  • For the ADS8321 specifically, there is a “tSMPL” that after CS goes low the sampling switch is closed for 4.5 to 5 DCLOCK cycles.

    To answer your question directly, the sampling switch only closes for  4.5 to 5 DCLOCK cycles. Your sampling time is a fixed window of DCLOCK cycles.

    Also, the design team has begun looking into your RON question for the switch.

     

    Thanks,

    Reed

  • Hello Andy,

    I have received an answer from the design team about the switch on resistance for the ADS8321. Ron for both IN+ and IN- is typically 50 ohms. The resistance will change slightly with the input voltage and with temperature. The design team ran a temperature sweep (-40C to 85C) and an input voltage sweep (0V to 5V) -- Ron will be between 32.5 ohms and 73.0 ohms.

    If you need a specific resistance based on input voltage and temperature please let me know.

    Thank you,

    Reed