nettron1000
New Member
Two 74154's would be the maximum you can drive directly from 8 data outputs, to drive more you would need to include some type of addressing scheme as part of your circuit with accompanying programing, this will make it abit more complex to build.
Most, if not all, mux's have an enable pin that you have to make either high or low to "choose" the chip, using this scheme you can control upto 16 74154's for a grand total of 256 addressable multiplexed outputs.
Obviously trying to fit 17+ 74154's ( 24 pins each ) on a PC board would consume an enormous amount of board realestate. why do you want so many outputs or what is the application ?
Most, if not all, mux's have an enable pin that you have to make either high or low to "choose" the chip, using this scheme you can control upto 16 74154's for a grand total of 256 addressable multiplexed outputs.
Obviously trying to fit 17+ 74154's ( 24 pins each ) on a PC board would consume an enormous amount of board realestate. why do you want so many outputs or what is the application ?