ADC Resolution & Quantization Noise Calculator
Enter the known values and run the calculation.
Overview
Relate converter resolution to quantization noise and usable dynamic range when specifying acquisition hardware.
This tool converts ADC full-scale range and nominal bit depth into LSB size, ideal quantization noise, and ideal full-scale SNR.
It is useful when comparing digitizers, checking whether a range is too wide, or explaining why a low-level signal looks rough before any analog noise is added.
The math and how it's used
LSB size is full-scale range / 2^N for an N-bit converter.
RMS quantization noise is modeled as LSB / sqrt(12), and ideal full-scale sinewave SNR is approximated as 6.02N + 1.76 dB.
Use this when ADC bit depth needs to be translated into ideal code width and the usual quantization-noise floor.
It is the ideal converter story. Aperture jitter, front-end noise, distortion, reference quality, and layout will usually set the real floor well before the textbook limit does.
Limits of the result
Real converters are also limited by analog front-end noise, INL, DNL, clock jitter, aperture effects, and range selection mistakes.
Use this as the ideal floor, not as a promise of the full measurement chain.