Other Parts Discussed in Thread: ADS127L01, , ADS1298
Brian Lizon:
i would like to reproduce the FFT plot example as shown in Bryan Lizon 's report " Fundamentals of Precision ADC Noise Analysis" released on 2020. figure 9. Example ADS127L01 FFT with a 4-kHz, –0.5-dBFS input signal
i use a function generator (prosim 8 made by fluke) to inject 1 mV amplitude sine wave @ 10 Hz to AFE ( 24 bits ADS1298R ). data is collected from FPGA at 2k sps, i use matlab to convert the csv file into FFT for the noise plot. unfortunately, the noise plateau was in the range of -3 dB.
i start suspecting my FFT or data collection. i would like to receive your help in figure out the mistake i made during the data acquisition process.
i will appreciate if you
1) share with me an example of raw data collection ( such as a csv file) with FFT post processing so that i can learn your noise plot in dB vs. frequency to understand how you process the data.
2) i have enclosed my data collection and FFT on one channel so that you can see how i process the data, hopefully, you can figure out why or how i made the mistake in the post data processing.
thanks
jason 978-773-0936TI_jan25.pptxsine10Hz_1mV_jan23-RawEcg2k.xlsxTI_noise_brian.pdf
or DDC->PADC.