anyone got a copy of the mk5375 pdf or information pleassssse

I have a hardcopy datasheet for MK5375 "ten number repertory tone/pulse dialler". Pretty detailed, 11 pages. It's in the Mostek 1984/5 Microelectronic Databook.

I would be willing to scan it if you can't find the info readily elsewhere.

Do you already have this chip? Given its age, it might be hard to buy, I would guess there are more modern and available ones.

Mike.

So go to the store, buy a really cheap touchtone phone, and extract the needed IC and keypad from there. Any other needed components will also be provided by that phone. You can even simply repackage it, or if it fits, just use the phone intact.

The earliest use of touch tones outside of telephones was to remotely control things over radio. And the earliest touch tone pads for that use were surplus touch tone pads from telephones. It was only a few years later, as IC integration became better, that there were touch tone encoder ICs available to the hobbyist, so they could build them up from scratch. But usually that entailed by a costly keypad that happened to go with the costly IC (which despite the cost was smaller than the telephone pads, and the ICs made the encoder far more stable and reliable than a lot of the interim solutions for the task).

Now it's gone full circle. The cheapest and most readily available source is the phone once again.

Same thing applies every time someone needs an IC to build a digital clock. If they want a single IC to do the task, they are generally better off buying a commercially built digital clock.

The only thing this wouldn't apply to is if someone is actually building in quantities, in which case buying a commercial unit starts becoming too expensive once you get beyond a certain level of units.

Michael