Binary Weighted Resistor DAC (1)

3-bit binary weighted resistor DAC Let the 3-bit input digital voltages be each represented by 5 volts for 1 and 0 volts for a “0”. Use a single pole double throw (SPDT) switch to set each input bit to either “0” or “1”. At the output of the circuit, add an inverting op-amp with appropriate choice of resistors so that the final output voltage is between 0 to 20 volts.