Use this tool to find the Signal-to-noise ratio of an Analog-to-Digital Converter. Enter the number of bits (N) and it will calculate the SNR.
Formula
SNR = 6.02*N + 1.76
where N is the number of ADC bits.
Background
What is SNR of an Analog-to-digital converter?
The SNR refers to the Signal-to-Noise Ratio of an Analog-to-Digital Converter (ADC).
The ADC is a vital component in the digital processing of analog signals, transforming them into a series of digital codes.
The ADC SNR indicates the ratio between the signal power and the noise power introduced during the conversion process. The SNR calculator and measurement guide provides an overview.
A higher SNR value implies better signal quality and accuracy.
It is an essential metric in assessing the performance of an ADC as it determines the ability of the converter to distinguish between desirable and unwanted signals. In practical terms, a higher ADC SNR indicates a more precise and reliable conversion, enabling enhanced precision and fidelity in various applications such as communications, audio recording, and measurement systems.
What is the Number of bits in an ADC?
The number of bits, N represents the resolution of the Analog to digital converter. The higher the resolution the greater the precision and accuracy. For example with a maximum voltage of 5 Volt, a 10 bit ADC has a resolution of 4.9 mV while a 14 bit ADC has a resolution of 0.3 mV. Use the ADC bit resolution calculator.
The 14-bit ADC therefore provides higher fidelity than the 10-bit ADC.
The following table shows the SNR and resolution as a function of number of bits in the ADC. The reference voltage is +5V in all cases.
| Number of Bits | Resolution (mV) | SNR (dB) |
|---|---|---|
| 8 | 19.5 | 50 |
| 10 | 4.9 | 62 |
| 12 | 1.2 | 74 |
| 14 | 0.3 | 86 |
| 16 | 0.08 | 98 |
| 18 | 0.02 | 110 |
| 20 | 0.005 | 122 |
| 22 | 0.001 | 134 |
| 24 | 0.0003 | 146 |
Based on the formula, SNR = 6.02*N + 1.76, it can be seen that the SNR increases by about 6 dB for every additional bit.
As well, the ADC resolution goes from 19.5 mV to 0.3 µV. The smaller this number, the greater the ability of an ADC to detect very weak signals in the presence of strong ones.
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