simple D/A converter

elektorjuly/august 1983 1 Parts List Resistors R1=100k simple D/A converter given in figure 2 in which the latch (I C1), comparator (1C2 and 1C3) and the counter (IC4) are immediately evident. Other stages are a clock oscillator (Nl, N2 and N3) and a buffer for the analogue output (105). The integrator (R3 and C2) is pre- ceded by two CMOS gates the supply of which can be derived from a reference voltage. To start reading of the data, an enable pulse must be given at pin 11 of IC1. The oscillator can be switched on and off by the input at f; if this input is open, the oscil- lator will do just that! It is possible to connect a second, external oscilla- tor to this input, in which case, the clock frequency will be that of the Special ICs are available to achieve an analogue output from a computer. A digital to analogue converter using these beasts can be simple but expensive. However, a simple cir- cuit can also be constructed from standard components. The circuit described is simp...