#1701 CD4051 8 Way Switch Multiplexer

all right chip of the day everybody loves chip of the day so today we are going to have a special request yes a chip of the day spy special request one of my viewers wanted to see a CD 4051 so this data sheet covers 4051 52 and 53 we'll be looking at the 4051 and it's a really nice part I like the way they drew it it is an eight-way switch it's an analog switch so there's an input or an output is bidirectional so you can select which one of the eight channels you want to have and that's selected by this uh binary code ABC so whatever code you have here you can select 0 through 7even there's also an extra switch that's an inhibit switch so you can you can just completely disconnect uh The Circuit by uh raising this inhibit pin and that will disconnect this uh this switch here all right so um it is a 4,000 series seos part so it's good from uh 3 volts to 20 volts um the um range with which the analog so this is a an analog device so that the range of the analog is basically the range of the voltages that you put in to a certain extent we we'll get to that um let's take a look at the uh let's see here this is um a use case typical application they have a microcontroller controlling the four bits and they're using this as a SK a keyboard scanner so they have a keyboard over here and they basically scan everything has to pull down so as you scan along you just see zeros everywhere and then when there's a button switch it goes up to this 3.3 and then you'll see a full scale on your a to D um so that's the way this particular uh application is made so I figured hey why don't we go ahead and use their application so here is um here's the device so I have a microcontrol let me put on some uh put on some power here all right let's Zoom way down so you can see it operate it's a small display there we go so you can see it's counting it's counting five six 7 then zero so the first number is the channel number and we can see on channel three there's something but on channels 4 5 6 7 0 1 and two there's 's nothing but on Channel 3 there's 512 okay so this program uh cd4051 so this program is going to cycle through everything and run the uh output of the multiplexer into one of the analog pins and you get uh bits between Z and 1023 so um right now it looks like it's about halfway and let me let me change this all right so it's going to go around one two three this time it's 1023 because I pulled that line up to 5 volts okay and otherwise I have it set to halfway between uh 0o and five and it gives me the uh the 512 all right so uh right now it's on on I'm inputting something on that pin let me put it on zero so when it goes around the uh zero channel should have some voltage on it now uh no oh one I'm I don't know where zero is so one one has the voltage on it now but anyway yeah you can move these around to different uh different channels let's see which channel I got this time I got channel five that time so yeah there you go I have pull Downs just like their circuit I have pull Downs on all the pins and um I have one one pin that I'm that I'm modulating I'm making it go up and down um and yeah so there you go like I said it's bir directional so you can um input one of eight things or you can output one thing and select which one of eight things you want to Output so that works it works works both directions all right there you go chip of the day was a CD [Music] 4051

Channel: IMSAI Guy

Views: 5,019

Keywords: s100, s-100, cpm, cp/m, cpm80, intel 8080, 8080, 8085, zilog z80, vintage computer, vintage computing, IMSAI, IMSAI 8080, ALTAIRTTL CPU, cpu design, eagle cad, eagle pcb, 8-bit CPU, 8bit CPU, diy cpu, 74181, 74381, 74382, ALUZeta, Zeta2, ROMWBW, Zeta SBCelectronic test equipment, vintage electronics, DIY electronics, electrical engineering, electronic engineering, electronics, PCB design, Circuit design

Id: im6ojpE49ec

Length: 5min 22sec (322 seconds)

Published: Mon Dec 04 2023