Assuming an existing set of Sigma-delta ADC output sequences, two methods for calculating the corresponding Snr are described below. The CIW window command where data is exported by cadence is: ocprint (? Output "Export directory/output file name" V ("/Saved circuit node"? Resultsdir "cadence Emulation Data Catalog/PSF"? Result "" Tran-tran ")? From the start time to the cut-off time? Step Step).
Method One:
The first method is to use the He Lenian "analog and digital conversion circuit," the MATLAB program code to calculate, and thus not described in detail.
Method Two:
This will focus on method two. This method is used to calculate the PSD directly in the Sdtoolbox. Simulink test systems, such as, are mainly composed of "from File" and "PSD".
Where the frequency and PSD settings see the previous logs. Here are a few things to ask:
(1) The "from File" module is used to load the input data, where the input data needs to be a two-dimensional array, in a row. The first line is time, and the second behavior is ±1.
(2) The "from File" sampling time is set to the sampling time of the Sigma Delta ADC.
(3) If the data in a time period is truncated from cadence, then note that the actual simulation time starts at 0 and is sampled before the "from File" is taken to the time period data, so these sampling points are not considered and need to be in the PSD module "number of Transient Points "Inside is set, which means that the number of points before the calculation.
Respectively is the simulation result of method one and method two, the two are basically consistent.
(Original address: http://www.eetop.cn/blog/html/25/853625-51906.html)
[Turn] Two Sigma-delta ADC Snr simulation methods