Question

For the 4 bit DAC shown below, the Analog output voltage is (Assume ideal Op-amp).

• A.
  $-1.11V$
• B.
  $-2.4V$
• C.
  $-3.25V$
• D.
  $-3.75V$

Answer 1

The correct option is D

$-3.75V$


$I=\frac{10-0}{10K}=1mA{I}_1=\frac{I}{8}+\frac{I}{16}=\frac{1}{8}+\frac{1}{16}=\frac{3}{16}mA{V}_0=-I_1\times 20K=\frac{-3}{16}\times 20=\frac{-15}{4}=-3.75Volts$