示例

計算以下條件下的 SNR、THD、SINAD 和 ENOB：

MaxRMSSignal = 1.76V_RMS

VRMS RMSDistortion = 50μV_RMS

RMSNoise = 100μV_RMS

答案

$SNR\left(dB\right)=20log\left(\frac{1.76 V_{RMS}}{100 \mu V_{RMS}}\right)=84.9 dB$

$THD\left(dB\right)=20log\left(\frac{50 \mu V_{RMS}}{100 \mu V_{RMS}}\right)= -90.9 dB$

$SINAD\left(dB\right)=20log\left(\frac{1.76 V_{RMS}}{\sqrt{{\left(100 \mu V_{RMS}\right)}^2+ {\left(50 \mu V_{RMS}\right)}^2}}\right)=83.9 dB$

$SINAD\left(dB\right)=-20log\left(\sqrt{{10}^{\left(\frac{-84.9 dB}{10}\right)}+ {10}^{\left(\frac{-90.9 dB}{10}\right)}}\right)=83.9 dB$

$ENOB= \frac{83.9 dB-1.76 dB}{6.02}=13.65$