the8thhabit
Member level 1
Hello!
I am designing a noise shaping SAR ADC in CADENCE and I have a question in FFT simulation.
I used a 10-bit CDAC, OSR = 4, fs = 20MHz, sampling count = 2048.
Then the bandwidth is fs/2/OSR, so 2.5 MHz.
If I set k=31 in the equation k*fs/sample count, the fin (input frequency) would be 0.302MHz.
I ran the FFT simulation until 2048*50ns = 102.4us and then ran the FFT simulation.
In this case, I was wondering if it is correct to set the end frequency to 2.5MHz, which is the bandwidth, as shown in the photo below.
I am designing a noise shaping SAR ADC in CADENCE and I have a question in FFT simulation.
I used a 10-bit CDAC, OSR = 4, fs = 20MHz, sampling count = 2048.
Then the bandwidth is fs/2/OSR, so 2.5 MHz.
If I set k=31 in the equation k*fs/sample count, the fin (input frequency) would be 0.302MHz.
I ran the FFT simulation until 2048*50ns = 102.4us and then ran the FFT simulation.
In this case, I was wondering if it is correct to set the end frequency to 2.5MHz, which is the bandwidth, as shown in the photo below.
