I'm designing an analog circuit with a regulated +/-12V supply. I want to include a 4000 series CMOS logic device to switch a sub-circuit at sub-Hz frequency.
I haven't worked out all the details but, at this stage, using ground as Vdd and -12V as Vss looks like a convenient way to go. Is there any reason why this is inadvisable? Any caveats? (Proper care will be taken to ensure that no pin will be pulled outside Vdd and Vss).
I've done this, no problems at all except make sure it's *very* clearly marked on the circuit diagram for the repair technician.
No problem. Older 4k cmos would latch up and short the supply if you transiently forward-bias an ESD diode, which gets worse at high supply voltages. Maybe watch out for that, with the unusual supplies.
Noted, and thanks. I'm not sure yet if this will go into production.
Thanks.
The idea of "Ground" is a ghastly human simplification that mostly serves just to make schematics not look messy but hides the real truth!
piglet
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