For the 3-bit 2ⁿ -R D/A converter of Figure, calculate the analog output voltage when the input is (a) 100, and (b) 010.

Solution

a. For the binary input 100, switches controlled by B₀,¯B₁, and ¯B₂ will be closed. A path is then produced between the output Vo and point 4, where the voltage is equal to V_ref/2.

The analog output voltage is therefore V_ref /2. b. For the binary input 010, switches controlled by ¯B₀, B₁, and ¯B₂ will be closed. A path exists between Vo and point 6, where the voltage is equal to Vref /4. The analog output voltage is thus V_ref/4.