• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 30 subscribers
  • Views 2996 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

PCM3140-Q1: 交流单端模拟输入INM的串接电容作用是什么？

jiahao zhang
Prodigy 10 points
Part Number: PCM3140-Q1

Tool/software:

你好，

请问7.3.3的交流模拟输入

INM的串接电容作用是什么？是否是必要的，可以否直接INM接地？

如果直接接地请问有什么影响

  • 0
    TI__Mastermind 27280 points

    HI Jiahao,

    Apologies, I don't know chinese.

    The AC-coupling capacitor will block DC voltage from the signal source and allow the IC to automatically bias the input signal to the common mode voltage of the ADC.

    If the analog input signal line are unused we recommend AC-coupling them to GND with a 0.47uF capacitor

    If the signal is AC-coupled single-ended, then we recommend ac-coupling INM to gnd.

    If the signail is dc-coupled single-ended, INM can be connected directly to gnd

  • 0 in reply to Daveon Douglas
    Prodigy 10 points

    hi:

    ''If the signal is AC-coupled single-ended, then we recommend ac-coupling INM to gnd.''

    Do u mean that use ac-coupling INM to gnd with 0.47uF capacitor?

  • 0 in reply to jiahao zhang
    TI__Mastermind 27280 points

    Hi,

    If a differential input pair is unused, meaning customer designate as NC, then we recommend to ac couple INP/INM to GND with 0.47uF cap.

    If the signal is AC-coupled single ended, then INP/INM should have matching 1uF capacitors.