R-2R TYPE A/D CONVERTING CIRCUITRY

摘要

Thr R-2R type D/A converter comprises two series circuit each comprising a resistor and a switch. One series circuit is connected between one end of a ladder resistor circuit and the ground. The other series circuit is connected between the other end of the ladder resistor circuit and the ground. The switches in the series circuits are selectively turned on/off, so that an output signal may be supplied in either direction. Analog circuits are connected one to each terminal of the R-2R type D/A converter circuit. By turning on/ off the switches of the circuits, a D/A converter output signal may be supplied selectively to either analog circuit. Since the switches of the series circuits are not located in the analog signal line, the D/A converted output signal can be supplied selectively to the two analog circuits.