Question

An 8-bit unipolar (all analog output values are positive) digital-to-analog converter (DAC) has a full-scale voltage range from 0 V to 7.68 V. If the digital input code is 10010110 (the leftmost bit is MSB), then the analog output voltage of the DAC (rounded off to one decimal place) is _________.

Hint:

For an \( n \)-bit DAC, the output voltage is given by \( V_{\text{out}} = \frac{\text{Digital Code}}{2^n - 1} \times V_{\text{full scale}} \), where \( n \) is the number of bits.

Answer 1

Correct Answer: 4.5

For an 8-bit DAC, the output voltage is given by the formula: \[ V_{\text{out}} = \frac{\text{Digital Code}}{2^8 - 1} \times V_{\text{full scale}} \] where the digital input code is \( 10010110_2 = 150 \) in decimal, and the full-scale voltage is \( 7.68 \, \text{V} \). Substituting the values: \[ V_{\text{out}} = \frac{150}{255} \times 7.68 \, \text{V} \approx 4.5 \, \text{V}. \] Thus, the analog output voltage of the DAC is \( 4.5 \, \text{V} \).