Question

A temperature range from $-{20}^{\circ }Cto{50}^{\circ }C$ is to be measured with a resolution of ${0.2}^{\circ }C$. The minimum bits required to get a matching dynamic range of the temperature sensor will be

• A. 8
• B. 4
• C. 6
• D. 9

Answer 1

The correct option is D 9

Given,
temperature range
$({50}^{\circ }-(-{20}^{\circ }\left)\right)={70}^{\circ }C$

$Resolution={0.2}^{\circ }C$

Resolution relative to range
$=\frac{0.2}{70}=0.00286$

For N bit ADC

$Resolution=\frac{1}{2^N-1}=0.00286$

$2^N=350$

$N\underset{–}{\sim }9$