ADC Resolution Calculator Formula
Understand the math behind the adc resolution calculator. Each variable explained with a worked example.
Formulas Used
LSB Size
lsb_mv = v_ref / pow(2, bits) * 1000Quantization Levels
num_levels = pow(2, bits)Dynamic Range
dynamic_range_db = 20 * log10(pow(2, bits))Variables
| Variable | Description | Default |
|---|---|---|
bits | ADC Bits(bits) | 12 |
v_ref | Reference Voltage(V) | 3.3 |
How It Works
ADC Resolution
Formulas
LSB = V_ref / 2^N
Levels = 2^N
Dynamic Range = 20 x log10(2^N) dB
N is the number of bits. Each additional bit doubles the resolution and adds 6 dB of dynamic range.
Worked Example
12-bit ADC with 3.3 V reference.
bits = 12v_ref = 3.3
- 01Levels = 2^12 = 4096
- 02LSB = 3.3 / 4096 = 0.000806 V = 0.806 mV
- 03Dynamic range = 20 x log10(4096) = 72.2 dB
Frequently Asked Questions
What is ENOB?
Effective Number of Bits accounts for real-world noise and distortion. A 12-bit ADC might have 10.5 ENOB due to noise.
Does higher resolution mean better accuracy?
Not necessarily. Accuracy depends on reference voltage precision, linearity errors, and noise floor.
How does sampling rate relate to resolution?
They are independent specifications. Oversampling can trade speed for effective resolution (averaging).
Ready to run the numbers?
Open ADC Resolution Calculator