M1AFS600-PQ208 Datasheet, PDF (122/334 Pages) Microsemi Corporation – Fusion Family of Mixed Signal FPGAs

Device Architecture
Ideal Output
Actual Output
0...01
0...00
Offset Error = 1.5 LSB
Input Voltage to Prescaler
Figure 2-86 • Offset Error
Resolution
ADC resolution is the number of bits used to represent an analog input signal. To more accurately
replicate the analog signal, resolution needs to be increased.
Sampling Rate
Sampling rate or sample frequency, specified in samples per second (sps), is the rate at which an ADC
acquires (samples) the analog input.
SNR – Signal-to-Noise Ratio
SNR is the ratio of the amplitude of the desired signal to the amplitude of the noise signals at a given
point in time. For a waveform perfectly reconstructed from digital samples, the theoretical maximum SNR
(EQ 14) is the ratio of the full-scale analog input (RMS value) to the RMS quantization error (residual
error). The ideal, theoretical minimum ADC noise is caused by quantization error only and results directly
from the ADC’s resolution (N bits):
SNR_dB[MAX] = 6.02_dB  N + 1.76_dB
EQ 14
SINAD – Signal-to-Noise and Distortion
SINAD is the ratio of the rms amplitude to the mean value of the root-sum-square of the all other spectral
components, including harmonics, but excluding DC. SINAD is a good indication of the overall dynamic
performance of an ADC because it includes all components which make up noise and distortion.
Total Harmonic Distortion
THD measures the distortion content of a signal, and is specified in decibels relative to the carrier (dBc).
THD is the ratio of the RMS sum of the selected harmonics of the input signal to the fundamental itself.
Only harmonics within the Nyquist limit are included in the measurement.
2-106
Revision 4