Question

A digital to analog converter has full scale ouptut of $4.2V$. The converter has resolution close to $18mV$, then bit size of digital to analog converter will be

• A. $8$
• B. $10$
• C. $6$
• D. $12$

Answer 1

The correct option is A $8$

Resolution, $R=\frac{V_0}{2^N-1}=18mV$

$\text{where}{V}_0=\text{Full scale output voltage}=4.2V$

$N=$ bit size

So, $\frac{V_0}{2^N-1}=18mV$

$\Rightarrow \frac{4.2}{18\times {10}^{-3}}=2^N-1=233.33$

$\therefore N=8$