Analog-to-Digital Conversion › lesson 31 of 100 · Intermediate

Calculate Signal-to-Noise and Distortion

This lesson is part of the Analog-to-Digital Conversion course and will teach you how to calculate signal-to-noise and distortion ratio for ADC signals. After completing this lesson, you will be able to calculate and analyze the quality of ADC signals.

The signal-to-noise and distortion ratio (SINAD) is a measure of the quality of an analog-to-digital converter (ADC) signal.

In a real-world scenario, consider a digital audio player that uses an ADC to convert analog music signals into digital signals. The signal-to-noise ratio (SNR) is the ratio of the desired signal power to the noise power, while the total harmonic distortion (THD) is the ratio of the distortion power to the signal power. The signal-to-noise and distortion ratio (SINAD) is the ratio of the desired signal power to the total power of noise and distortion.

To calculate SINAD, you need to measure the power of the desired signal, noise, and distortion. This can be done using a spectrum analyzer or a signal processing software.

The SINAD is calculated using the formula: SINAD = 10 · log10((P_signal) / (P_noise + P_distortion))

示例

• A 12-bit ADC has a SNR of 60 dB and a THD of 0.1%. What is the SINAD?To calculate SINAD, you need to convert the SNR and THD into power ratios.
• A digital signal has a SINAD of 40 dB. What is the ratio of signal power to noise and distortion power?To find the ratio, you need to convert the SINAD from decibels to a power ratio.
• An ADC has a noise power of 0.01 mW and a distortion power of 0.001 mW. If the signal power is 1 mW, what is the SINAD?To calculate SINAD, you need to use the formula and plug in the values.

完整课程用 5 道题核对每一课，随你的层级调整，并记住你的位置。