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
- Maximum Analog Input Voltage
- Minimum Analog Output Voltage
Background
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
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.
ADC Resolution Table
The following shows the ADC resolution for an input voltage range of 5V
Number of ADC Bits | ADC Resolution (Volt) |
1 | 2.5 |
2 | 1.25 |
3 | 0.625 |
4 | 0.3125 |
5 | 0.15625 |
6 | 0.078125 |
7 | 0.0390625 |
8 | 0.01953125 |
9 | 0.009765625 |
10 | 0.0048828125 |
11 | 0.00244140625 |
12 | 0.001220703125 |
13 | 0.0006103515625 |
14 | 0.00030517578125 |
15 | 0.000152587890625 |
16 | 0.0000762939453125 |
17 | 3.814697265625E-05 |
18 | 1.9073486328125E-05 |
19 | 9.5367431640625E-06 |
20 | 4.76837158203125E-06 |
21 | 2.38418579101562E-06 |
22 | 1.19209289550781E-06 |
23 | 5.96046447753906E-07 |
24 | 2.98023223876953E-07 |