“Cheap discrete DAC with CD4007 IC
A fifty-year old DAC design with two CD4007 CMOS ICs, but still good enough to get a grasp how DACs work.
The output (which is inverted) should act according to the input bit pattern.
Examples with 3.3V (CD4007UBE specified for 3V-18V):
111111 (representing 0d) = 0.0V
011111 (representing 32d) = 1.6V
001111 (representing 48d) = 2.5V
The better the tolerances of the resistors (you need a lot :-D), the better the results. Use any input device you like (e.g. µC, mechanical switches). Also easily scalable to 9bit, 12bit, ….”