[sdiy] ETI447

[Rönnberg Niklas]

Well, I understand that since pin 1 (Vdd) and pin 8 (Vss) are both
connected to zero reference voltage. Pin 13 and pin 16 are not used
according to the datasheet, but why is pin 16 connected to zero reference
voltage in the ETI design (and pin 13 is not connected)?

Maybe this is just some mistake in the original pcb layout and doesn't
affect anything at all, and maybe not...

Best regards

/a rather confused Niklas


-----Original Message-----
From:	Ken Stone [mailto:sasami at hotkey.net.au]
Sent:	Wed 7/7/2004 11:46 AM
To:	Rönnberg Niklas
Cc:	synth-diy at dropmix.xs4all.nl
Subject:	Re: [sdiy] ETI447
>
>I have some questions about this circuit. I think that the use of IC9, a
>4049 CMOS, are quite smart, but why are pin 16 connected to zero reference
>voltage?

because the chip is not being used as a digital chip. It is being used as a
row of FETs. (a case of using it in a way it was not designed to be used)

Ken
_______________________________________________________________________
Ken Stone   sasami at hotkey.net.au or sasami at cgs.synth.net
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>