Sense

1.How does averaging increase the Signal to Noise ratio?
http://dsp.stackexchange.com/questions/19159/how-does-averaging-increase-the-signal-to-noise-ratio

2.Dithering/Averaging - To increase the resolution
http://dsp.stackexchange.com/questions/19782/improving-digitization-by-adding-white-noise-before-oversampling/19783#19783
http://www.analog.com/media/en/training-seminars/tutorials/MT-004.pdf

3.PRS clock source vs. fixed frequency clock

4.Why oversampling can reduce the system noise?

5.Ground loop basics
http://www.epanorama.net/documents/groundloop/basics.html#

6.How to understand "Hysteresis"?

7.What's the difference between functional requirements and performance requirements for the tt system?
Functional requirements:pass/fail. Performance requirements:numerical.

8.Edge and Core
The edge is the active area at the perimeter of the touch panel. The width of this area is 3.5mm and is independant of touch object size. The core is the active area bounded by the edge. [001-65293]

9.电容并联的作用

同种类型的电容并联作用主要是扩容。
不同种类型的电容并联一般是一个感性强、一个感性弱。

小容量电容高频信号易通过，大容量电容低频信号易通过。

大电容在低频时能提供好的通路，而在高频时由于其寄生电感的存在阻抗将变大而无法提供滤波通路，所以大电容不能滤高频，而小电容在低频时阻抗太大而无法提供滤波通路，所以不能共同一电容滤高频和低频。

电容并联的好处在于增大容值，减小容抗。
并联数量越多，效果越明显，不过成本就越高。

电解是用来滤低频，陶瓷是用来滤高频的。此外，电解有漏电电流，所以后面在接陶瓷来消除漏电流的。

在开关电源中，两个电容并联的作用为电容大的那个是用来滤波的，小的那个电容是用来消除大的电容在高频时产生的感性特性的！