My Inquiry
My Account
ADC Resolution Calculator
Calculate ADC LSB size, quantization error, ideal output code, ENOB-limited resolution, and minimum detectable voltage for ADC design and measurement planning.
Input Parameters
Results
LSB size is an ideal code width. Real ADC accuracy also depends on INL, DNL, offset, gain error, noise, reference tolerance, source impedance, and layout.
Equations Used
Codes: Full-scale codes = 2^N - 1
Ideal LSB: LSB = (VrefH - VrefL) / (2^N - 1)
Ideal code: Code = round((Vin - VrefL) / LSB)
Quantization error: ±0.5 LSB
ENOB LSB: Effective LSB = range / (2^ENOB - 1)
Frequently Asked Questions (FAQ)
Q1: What is ADC resolution?
ADC resolution is the number of digital codes available to represent the analog input range.
Q2: What is ADC LSB size?
LSB size is the ideal voltage step between adjacent ADC output codes.
Q3: Why is ENOB lower than nominal bits?
Noise, distortion, reference error, and analog front-end limitations reduce effective resolution.
Q4: Can a 12-bit ADC always measure 0.8 mV steps?
Only ideally. Real performance depends on noise, input source, reference quality, and calibration.
Q5: Should I use 2^N or 2^N - 1?
For endpoint code mapping, 2^N - 1 is commonly used; some datasheets use slightly different conventions.
