16 Channel Analog Multiplexer
This circuit is built around the chip CD4067, now called 74HC4067, it works like a single pole 16 throw rotary switch that can be controlled digitally. Clamping protection diodes are built in. Use resistors to enable this protection.
Pan and Zoom the Circuit for detailed Study here – Sixteen Channel Multiplexer
The ON Resistance of this chip is around 100 ohms and OFF resistance may be in Giga ohms. Use 74HC4067 for CMOS periphery. 74HCT4067 for a TTL environment.
16 Analog channels are controlled by a Digital User Interface circuit made of 4093 and 4029. Up/Down and Auto/Man are four Push-buttons. A LED Display to show the Channel Number that is selected.
The output of the Mux goes to OP07 whose high input impedance and low offset enables an accurate low impedance output that can go to the A/D Convertor, PLC Unit or DPM – Digital Panel Meter or voltmeter.