The Definition of Signal-Noise Ratio

Time : Jan 14 2015Source :analogtechnologies Author : Analog Click :
SNR (SIGNAL-NOISE RATIO) refers to the ratio of signal and noise which is in an electronic device or electronic system. The electronic signals come from external device and need to be processed through the equipment, and the noise is additional signal without rules and does not exist in the original signal, and this noise does not vary with original signal.
The unit of signal-noise ratio is dB, and its calculation method is 10 lg (PS/PN), in which PS represents the effective power of the signal and PN represents the effective power of the noise, and they can also be converted to voltage amplitude ratio relations: 20 lg (VS /.vn), VS represents the valid value of signal voltage and Vn represents the valid value of noise voltage. In audio amplifier, the higher the signal-to-noise ratio, the better performance it will have. Please see the below figure.