Magnus Danielson e93_mda at
Mon Mar 2 00:18:35 CET 1998

>>>>> "PS" == Paul Schreiber <synth1 at> writes:

 PS> It depends on WHICH CMOS.
 PS> The old Motorola MC14000 series could go to +18V. The newer 74HCxxxx is +5V, EXCEPT on some of the
 PS> analog mux chips 74HC4051, etc. They can take +-7.5V.

 PS> 4000 series was (is??) amazing stuff. The 4007 was used in lots
 PS> of EM gear as a VC resistor. I built a 24 channel data
 PS> acquisition circuit that had 141 4000 series chips in it that the
 PS> total power used was 7ma!! 

Paul, you are perfectly right. The old 4000 series is a good set of
building blocks which should not be ignored!

There are some problems with the old 4000 series which newer versions
have fixed, like the lock-up (see "The Art of Electronics" for a
discussion about it, I am sure that there are more briliant
discussions on the same subject) problem.

Things like 4066 (4 x CMOS-switches), 4053 (3 x 2-to-1 CMOS-switch
mux), 4067 (16-to-1 CMOS-switch mux) etc migth not be ideal they are
still being widely used all over.

Another personal favorite is the 4046 PLL building block, add some
passive components and you can do a simple PLL, add a frequency
divider and you can do a step-up PLL, VCO and Phase Detectors in one
package, neat. The 74HC4046 has higher frequency range (up to 13 MHz
instead of 2 MHz) but runs on only 5 V. You can also use it for FM and
PM demodulation.

Even if one doesn't target at a CMOS construction one migth learn a
lot of construction tricks just browsing througth the large set of
CMOS and TTL chips that is or was avaiable.

Still lacking a replacement source for some 74C components that needs
to run of +12 V... the 74HC familly isn't much of a help. Anyone
remember the 74C familly?

Magnus (Still learning from the past)

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