Multiplexer device using current switches - uses two parallel transistor for each switch, controlled by selection signal and third transistor providing circuit output

摘要

The multiplexer device employs at least 2 current switches, each having at least 3 switching transistors. The collector/emitter paths of 2 of these transistors (1, 2; 4, 5) are connected in parallel, with their collectors coupled to the supply potential (Vcc) via a resistor (9, 10). The collectors of the third transistors (3, 5) of the current switches are coupled together and to the supply potential via a further resistor (11). The bases of the first 2 transistors are controlled by a selection signal (A, A) or data signal, the base of the third transistor coupled to the collector terminal of the first resistor (9, 10), which pref. has a lesser resistance value than that of the further resistor (11). ADVANTAGE - High operating rate and noise immunity.