[sdiy] diff between A and B CMOS

[anthony]

I thought the distinction was much more convoluted that 'B' just standing 
for 'buffered'. B series have protection diodes and different fan-ins & 
fan-outs than the A series right? Or there is something different about 
fan-in and/or fan-out. Like maybe the threshold voltage changed with the 
load in A series, but not in B series?

I'm trying to think of an example where a 'UB' part would be different in 
the B series from the B series, but the examples I can come up with are the 
4069, the 4049 and the 4009. I don't think the 4069 ever existed as an A 
series part. The 4007 is often labeled, quite unnecessarilly I think, as 
'UB'. You find me a 4007 that is buffered and I'll show you a 4007 that 
doesn't work for anything but as a buffer/inverter. I can't remember if the 
4049 was around early enough to be an A series part either, but if you 
compared a 4049A to a 4049UB, they would be different.

Another big difference I think is the switch to a finer scale fabrication 
process that yielded denser, more durable parts.

More than just slapping a buffer on them in other words...

AA


> The change from the A to the B series was in the mid seventies. 1976 the 
> JEDEC
> standard was established. Before that, you cannot swap CMOS parts from
> different manufacturers as easy as today. They where often different
> electrically.
> The B means buffered. Buffered are the outputs. There are a few 
> exceptions.
> They are named UB (UnBuffered)
>
> The switch from A to B Series may be the reason. If special characteristic
> from the A series of a certain manufacturer is used.
>
> Harald
>
>
>
> Am Donnerstag, 1. Mai 2008 02:05:55 schrieb mark verbos:
>> When CMOS went from original A series to the B series, did the
>> resistance of 4016 analog switches change? Did the voltage swing at
>> the outputs of 4049s change?
>>
>> I'm working on a quantizer module that was designed in the 70s and
>> overhauled int he 90s with all new chips. The scale is now screwed up
>> and I'm wondering if its because of the switch from A to B series in
>> these chips.
>>
>> Anyway, I'm going to install a trimmer where there wasn't one. I'm
>> just curious really.
>>
>>
>> mark
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>