A microcontroller's ADC reads 512 on a 10-bit ADC with V_ ref = 3.3,text V . The input voltage is approximately:

Home › MCQs › Electronics Engineering › Question #11706

Electronics Engineering QUESTION #11706

Question 1

A microcontroller's ADC reads $512$ on a 10-bit ADC with $V_{ref} = 3.3\,\text{V}$. The input voltage is approximately:

$1.65\,\text{V}$✔️
$1.60\,\text{V}$
$1.00\,\text{V}$
$2.00\,\text{V}$

Correct Answer Explanation

$V_{in} = \dfrac{\text{ADC reading}}{2^{10}-1} \times V_{ref} = \dfrac{512}{1023} \times 3.3\,\text{V} \approx 0.5005 \times 3.3 \approx \mathbf{1.65\,\text{V}}$. Note the denominator is $2^{10} - 1 = 1023$, not 1024, because a 10-bit ADC has 1024 steps with the maximum code representing full-scale.

More Options