Other Parts Discussed in Thread: REF3025, ADS7947
Tool/software: Code Composer Studio
Dear colleagues
I used the ADC inside of F280049, I found one problem that the amplitude of signal would vary periodically.
So I do a test, To input a equal amplitude sine wave(50KHz, Vpp is about 0.5V~2V) to the pin A2 directly, and to use the oscilloscope to monitor this sine wave to make sure it is equal amplitude.
I used ADC inside of F280049 to sample(sampling rate is 400KHz, external reference ref3025), I got the result as below, the amplitude of sine wave vary periodically
If I used another equal amplitude non-sine wave to repeat this test,
I found the varying would become very much.
the case will not occur, when I use ADS7947 to repeat this test
Please help me to check this issue.
thanks!
br
jjl3