Adisimadc the fft output can be used like an analog spectrum analyzer to measure the amplitude of the.
Adc noise floor measurement.
Calculate the input noise of the converter which is the theoretical thermal noise floor limit ktb 174dbm at room temperature.
Since the noise is approximately gaussian.
Two s complement enabled in adc.
For example the noise floor of a 16 bit measurement system can never be better than 96db and for a 24 bit system the lower limit is limited to 144 db.
The noise floor of a measurement system is also limited by the resolution of the adc system.
We want to measure the noise floor of my adc ads61b29 12 bit 50msps.
For that we terminated the input of adc and captured the digital samples using fpga.
We are having some doubts in the calculation.
Fft noise floor 110db rms quantization noise level data generated using adisimadc figure 2.
In practice however the noise floor will always be higher than this due to electronic noise.
This is split into 2 experiments.
Determine the thermal quantization noise floor level in dbm either from the component vendor s data sheet or by measurement for a small signal input level on the order of 35dbfs.
Fft output for an ideal 12 bit adc input 2 111mhz f s 82msps average of 5 ffts m 8192 data generated from.
Calculate the normalized noise floor level in 1hz bandwidth by subtracting 10 log f sample 2 where f sample is given in units of hz.