Smaller multiplexers?

[OwossoBorn]

;D This is my first post!  I've spent a couple days reading through all the information and my head is spinning.

I have an old JL Cooper FaderBaby, (16)20mm 100k slide pots fixed at sending 'CC 7' on each of the 16 midi channels.  It works great and is the reason I started snooping around for 'something more.'  Upon taking it apart, I found that it uses two small (maybe 1/4"x1/2") Motorola 14051B multiplexers (also has the code XAA430 printed on it).  Is there any reason I couldn't find/use these itty bitty mults in place of the huge (in comparison) 4051's?  If so, I'd try creating a layout plan for it so  others could make their own smaller boards.   Oh,  also, the FaderBaby has a small chip (can't read the writing on it) that is obviously the 'controller' but doesn't look like anything I'm familiar with.  I know it was never re-programmable (according to mr. Cooper himself at a NAMM show) so is it some sort of FPGA or what?    I'm not at home, and I can't remember how many pins it has.

I saw somewhere on the site that TK was working on an FPGA of sorts.  Would this be a replacement to the PIC18F452?  It'd be fantastic for me to be able to have something much smaller than the current core board, but with the same programmablitiy/functionality.    I'd gladly help any futher research in any way that I can.  My soldering iron is tinned and ready to go! ;) 

I haven't been able to find any datasheets on the Motorola 14051b, or if it's even manufactured anymore.  I figure someone has to make a similar part that's just as small.  I want to make a control surface that fits in the palm of my hand with those same 20mm faders and add mute/solo/transport controls.

I realize that the core board is about as big as I want my whole controller to be, so I think I may have to make two boxes.  One that houses the core and a second to hold in my hand.

Any ideas on shrinking all this wonderful work?

8)-=Randy 

[moebius]

Hi,

Those are just Motorola branded 4051s in Surface Mount Device (SMD) Soic package, right? You'll find those by other manufacturers too - make your own layout and those will work ok.

Bye, Moebius

p.s. Semiconductor division of the Motorola is these days known as FreeScale.

p.p.s. I think TK is playing around with his Spartan III fpga board, but we'll just have to wait for the results  ;)

[OwossoBorn]

Looking at the datasheet for the 4051, I saw a smaller SOIC package that is exactly the same size as the Motorola 14051B.   The mouser order number is CD4051BM going for $.54 one at a time and $.441 ea for orders of 100.   The datasheet for that model say's it's the same pin layout as the Mot.14051B!   (no big whoop, I know...fun untangling the riddles)   All the traces for the layout I have are on one side.  I'm thinking I should be able to fit 8 of them onto a board the same size as the existing AIN board.  Either all on one side, or 4 on each side.  Has anyone done this successfully?  Is there a reason why a board couldn't have all 8 mults on it?

by the way, why can't buttons be used via the AIN board?

Thanks for the info on FreeScale Moebius.  I see you posted just as I was typing this message.  So is a Spartan III fpga board a suposed replacement for the core?

-=Cheers

[moebius]

The datasheet for that model say's it's the same pin layout as the Mot.14051B!   (no big whoop, I know...fun untangling the riddles)

Yeah,

It's the same part.. just remember that SMD parts are "mirrored" in relation to Thru-hole components  ;D

Is there a reason why a board couldn't have all 8 mults on it?

No. The reasons for MBHP designs are: A. Thru-hole components are easier to solder B. PCB size limit of the freeware version of the Eagle CAD C. Modularity.

by the way, why can't buttons be used via the AIN board?

I thought this was possible with some tweaks?!?

So is a Spartan III fpga board a suposed replacement for the core?

I think TK's not going to "reinvent the wheel" or redesigning the Midibox, but looking for new challenges better suited for fpga than a microcontroller/PIC.

Bye, Moebius