Analog/Digital MUX Breakout – CD74HC4067

This is a break­out board for the very handy 16-Chan­nel Analog/Digital Multiplexer/Demultiplexer CD74HC4067. This chip is like a rotary switch – it inter­nal­ly routes the com­mon pin (COM in the schemat­ic, SIG on the board) to one of 16 chan­nel pins (CHANxx). It works with both dig­i­tal and ana­log sig­nals (the volt­age can’t be high­er than VCC), and the con­nec­tions func­tion in either direc­tion. To con­trol it, con­nect 4 dig­i­tal out­puts to the chip’s address select pins (S0-S3), and send it the bina­ry address of the chan­nel you want (see the datasheet for details). This allows you to con­nect up to 16 sen­sors to your sys­tem using only 5 pins!Since the mux/demux also works with dig­i­tal sig­nals, you can use it to pipe TTL-lev­el ser­i­al data to or from mul­ti­ple devices. For exam­ple, you could use it to con­nect the TX pins of 16 devices to one RX pin on your micro­con­troller. You can then select any one of those 16 devices to lis­ten to. If you want two-way com­mu­ni­ca­tions, you can add a sec­ond board to route your microcontroller’s TX line to 16 device’s RX lines. By using mul­ti­ple boards, you can cre­ate sim­i­lar arrange­ments for I2C, SPI, etc.The inter­nal switch­es are bidi­rec­tion­al, sup­port volt­ages between ground and VCC, have low “on” resis­tance and low “off” leak­age, and to pre­vent crosstalk, per­form “break-before-make” switch­ing. The board also breaks out the chip’s “enable” pin, which when dri­ven high, will com­plete­ly dis­con­nect the com­mon pin (all switch­es “off”).Fea­tures:2V to 6V oper­a­tion“On” resis­tance: 70 Ohms @ 4.5V6ns break-before-make @ 4.5VWide oper­at­ing tem­per­a­ture range: ‑55C to 125CDoc­u­ments:Schemat­icEagle FilesDatasheetbil­dr blog – CD74HC4067GitHubRelated