CMOS switches revisited

[gstopp at fibermux.com]

     Larry,
     
     CMOS switches are bi-directional - treat them like toggle switches. 
     The only restrictions are to keep the voltages going through them in 
     between the power supply rails. For example if you power a 4016 
     between ground and +15, don't let any negative voltages get to any 
     pins.
     
     Yes the 4053 is a triple SPDT switch. Pinout:
     
     Switch    X   Y    Common  Control
     ------------------------------------
        A      12  13     14      11
        B      2   1      15      10
        C      5   3      4       9
     
     Power: V+ = 16, V- = 7, Ground = 8
     
     Re: CA3080's - they are not op-amps, they are OTA's (that stands for 
     "operational transconductance amplifier"). They are almost always used 
     in synthesizers as either VCA's or voltage controlled current sources 
     (kinda like a voltage controlled resistor but different). Sometimes 
     they are used as comparators or non-linear waveshapers. But they are 
     definitely not interchangeable with op-amps.
     
     Have fun,
     
     - Gene
     gstopp at fibermux.com


______________________________ Reply Separator _________________________________
Subject: CMOS switches revisited
Author:  ldavid at lae.lad.gmeds.com at ccrelayout
Date:    1/31/96 1:13 PM


Thanks everyone for helping me with the 4016.  Now I have a few more questions. 
     
     
First, are CMOS switces directional?  Some people said pin 3 and 4 of the 4016 
were signal b in and out respectively, and some said it was the other way 
around.  
     
Second, there's a 4053 in this ckt too, and I have assumed it is a series of a/b
     
switches (it's used to choose between saw and pulse waves).  Anybody know the 
pinout off the top of your head?  I ask because only 2 switches are used and 
some of the other pins are grounded or left hanging and I want to be careful if 
I go in and start cutting traces that I don't screw something up.
     
Third, there are a couple CA3080s in the ckt, which I always thought were 
opamps, but they sure don't look like opamps in this ckt.  Can someone enlighten
     
me?  I realize it's scandalous that I am an EE and I don't know this stuff, but 
as I have already explained to one person, it is not uncommon. :)  I had one 
class where I *may* have learned about specific chips like these.  I did learn 
about the various semiconductor technologies (of the day) and some specific 
applications, but that was 8 or so years ago, and I haven't done anything in 
electronics since.  Anyway, thanks for your patience and your help!