# ADC Bit Resolution Calculator

## Introduction

This tool computes the voltage resolution or the smallest voltage that can be measured by an analog-to-digital converter (ADC).

Every ADC is the number of bits it uses to digitize samples of the analog input. An n bit ADC produces 2n discrete digital levels.

The larger the number n, the higher the resolution.

Enter:

• Number of bits
• Minimum Analog Output Voltage

## ADC Resolution Formula

An ADC accepts an analog voltage at its input and converts it to an n-bit digital value. A 12-bit ADC for instance produces 212 = 4096 discrete values at its output.

The analog resolution or the smallest value that can be measured by the ADC is given by the formula:

(Vmax – Vmin)/2n

where

• Vmax is the maximum input voltage
• Vmin is the minimum input voltage
• n is the number of ADC bits

The difference between Vmax and Vmin is the input voltage range

## Calculation Example

A 12 bit ADC with an input voltage range of 3.3 Volt has a resolution of 0.81 mV.

Increasing the number of bits, increases the ADC resolution and therefore the precision of the measurement.

ðŸ’¡A related concept is the Quantization Error of the ADC.

## ADC Resolution Table

The following shows the ADC resolution for an input voltage range of 5V