JHS_Muffuletta CMOS switches type??

[gymcon]

Hi
Since I do not own a Muffuletta and I'm very curious how the switching works, I would really appreciate if someone would be so kind and tell me the type of the 3 CMOS switches used in the circuit.
I think they are ADG xxxx ...something.
Thanks a lot.

[ElectricDruid]

The big ones are Analog Devices chips, that much is obvious. The smaller one might be, I can't quite see from that photo.

Checking their website and limiting the parametric search 24-pin devices only throws up three possibilities: ADG1414, ADG715 and ADG714. All are 8 x SPST switches. They use different interfaces (I2C or SPI) but all are serial-controlled, which implies to me that there's a processor somewhere between that "fuzz type" rotary switch and those switch ICs, although it's not the *only* option - just the easiest.

If this is correct, those chips should be 7.9x4.5mm 24-pin TSSOPs. If not, then I'm barking up the wrong tree and you can feel free to ignore me!

HTH,
Tom

[gymcon]

The big ones are Analog Devices chips, that much is obvious. The smaller one might be, I can't quite see from that photo.

Checking their website and limiting the parametric search 24-pin devices only throws up three possibilities: ADG1414, ADG715 and ADG714. All are 8 x SPST switches. They use different interfaces (I2C or SPI) but all are serial-controlled, which implies to me that there's a processor somewhere between that "fuzz type" rotary switch and those switch ICs, although it's not the *only* option - just the easiest.

If this is correct, those chips should be 7.9x4.5mm 24-pin TSSOPs. If not, then I'm barking up the wrong tree and you can feel free to ignore me!

HTH,
Tom

Well, thanks Tom. Now I feel really stupid, not to filter ADG chips by a number of pins 

Yes, I think that's a PIC microcontroller in the top left corner. What do you think would work better for the analog switching side of the similar circuit - optocouplers or CMOS switches?

BTW, I admire your work 

[ElectricDruid]

Yes, I think that's a PIC microcontroller in the top left corner.

Aha! Yes, so it is! A 12F1572 by the looks of it, one of the newer "enhanced" chips. That makes sense.

What do you think would work better for the analog switching side of the similar circuit - optocouplers or CMOS switches?

Personally, I'd go with the analog switches. They act more like "normal" switches, and they'll be easier to control.

BTW, I admire your work 

Thanks very much!

Tom