Quantization Noise Rechner
Berechnen Sie ideal SNR, LSB voltage, and quantization noise for any ADC resolution und voltage range.
Ideal SNR
74.00 dB
Ideal SNR vs ADC Resolution (bits)
Formel
Quantization Noise in ADCs
When an analog signal is digitized, the rounding to discrete levels introduces quantization noise uniformly distributed over one LSB.
Formulas
Ideal SNR = 6.02 x N + 1.76 dB (for a full-scale sine wave)
LSB = V_full_scale / 2^N
Quantization Noise RMS = LSB / sqrt(12)
Each additional bit of resolution adds approximately 6 dB of SNR. Real ADCs achieve slightly less due to thermal noise, linearity errors, and timing jitter.
Lösungsbeispiel
A 12-bit ADC with 3.3 V full-scale range.
- 01Ideal SNR: 6.02 x 12 + 1.76 = 74.0 dB
- 02LSB: 3.3 / 4096 = 0.000806 V = 0.806 mV
- 03Quantization noise RMS: 0.806 / sqrt(12) = 0.233 mV
- 04Quantization levels: 2^12 = 4096
Häufig Gestellte Fragen
Why do real ADCs not reach ideal SNR?
Thermal noise, jitter, INL/DNL errors, and aperture uncertainty all reduce the effective number of bits (ENOB) below the theoretical limit.
What is ENOB?
Effective Number Of Bits = (SINAD - 1.76) / 6.02. It measures how many ideal bits the ADC actually achieves in practice.
Does oversampling reduce quantization noise?
Yes. Oversampling by 4x effectively adds 1 bit of resolution (6 dB improvement) when combined with decimation filtering.
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