Using Uno R3 and would like to interface a multiplexer IC but don't know what family IC is acceptable. Will 7400 series work or do I need 74F, 74ALS or regular CMOS??
Jim
Any of them should work - the avrs have pretty substantial drive capability.
CMOS like the 74hc series is probably preferred.
thanks that helps
The relevant parameters to look at are the VIL and VIH of the 'receiving' IC and the VOL and VOH of the 'driving' IC.
So if the Arduino controls the multiplexer, the Arduino's worst case VOL (the highest value in the datasheet) should be lower than the VIL of the multiplexer (the lowest value in the multiplexer's datasheet) and the Arduino's worst case VOH (the lowest value in the datasheet) should be higher than the multiplexer's VIH (the highest value in the multiplexer's datasheet).
If the Arduino would 'send' e.g. a VOL that's above the VIL of the multiplexer but below the VIH of the multiplexer, the signal level would be in unknown territory for the multiplexer and the multiplexer can interpret it as either LOW or HIGH
You can find the Arduino's VOL and VOH in the datasheet of the processor that's used on the board; it might differ between e.g. a 328P (as used on an Uno) and a 2560 (as used on a Mega).
Other thing to look at is how much current the input of the multiplexer sinks/sources (IIL and IIH) versus how much the Arduino processor can drive (IOL and IOH); this is usually a non issue with input currents in the uA range and output currents in the mA range.