Capsense不能手动调整IDAC设置

嗨，安迪，
85%是默认的IDAC自动校准级别。
对于那些使用“直接”感测时钟的设计，设置IDAC以驱动基线85%左右，将有助于避免平点（关于平面点的更多细节，参见AN5.951中的5.3.2.1.2节）。
但建议在大多数设计中使用“自动”或“PRS自动”感测时钟。使用“PRS自动”或“自动”时钟，无论基线在哪里，平点都会消失，不会打扰你。该系统可以通过PRS感知时钟获得更多的EMI／EMC效益。
也就是说，如果你选择PRS感测时钟，你可以调整IDAC使基线更低，甚至在15%左右。然而，要么太高要么太低不利于制造业，因为你永远不知道制造业一致性的最坏情况是怎样的。
如果必须在某些设计中选择直接感测时钟（例如，长距离接近应用），最好确保基线总是高于平点区域。
谢谢，
赖安



     以下为原文
  Hi Andy,
 
85% is the default level of Single IDAC Auto-Calibration.
For those designs with using 'Direct' sense clock, Set IDAC to drive baseline around 85%, will be good for avoiding flat-spot(For more details about flat-spot, refer to Section-5.3.2.1.2 in AN85951).
But it is recommended to use 'Auto' or 'PRS-Auto' sense clock in most designs. With using 'PRS-Auto' or 'Auto' clock,  no matter where the baseline is, the flat-spot will be gone and won't bother you. And the system can get more EMI/EMC benefits with PRS sensing clock.
That is to say....if you choose PRS sense clock, you can tune IDAC to make the baseline lower, even around 15%. However, either too high or too low is not good for manufacture production, because you never know how the worst case of manufacturing consistence could be....
if you have to choose direct sense clock in some designs(e.g., long distance proximity applications), it is better to make sure baseline is always upper than flat spot area.
 
Thanks,
Ryan