另外，对于外部的电压基准也很重要，因为其输出阻抗和模拟输入一样有关系，同时一般在基准输入端加入一个RC滤波器！

设计AD7708的参考资料

1. AD7708 datasheet ;

http://www.analog.com/UploadedFiles/Data_Sheets/AD7708_7718.pdf

2.  AN-665: Channel Switching Using Σ-Δ ADCs

http://www.analog.com/UploadedFiles/Application_Notes/134059895AN665_0.pdf

3.  AN-615: Peak-to-Peak Resolution Versus Effective Resolution

http://www.analog.com/UploadedFiles/Application_Notes/483455032911909735055330198351486AN-615_0.pdf

4. AN-611: 50 Hz/60Hz Rejection on Sigma-Delta ADCs

http://www.analog.com/UploadedFiles/Application_Notes/4935337418894055612263500285AN611_0.pdf

5. AN-610: The PGA on Sigma-Delta ADCs

http://www.analog.com/UploadedFiles/Application_Notes/491258049043755745306704857AN610_0.pdf

6. AN-609: Chopping on Sigma-Delta ADCs

http://www.analog.com/UploadedFiles/Application_Notes/4896821591939255883340363218AN609_0.pdf

7. AN-608: Input Buffers on Sigma-Delta ADCs

http://www.analog.com/UploadedFiles/Application_Notes/488051407261865599679166589AN608_0.pdf

8.  AD7705.C code example

http://www.analog.com/zh/content/0,2886,760%255F%255F5450%255F5,00.html