What is the best logic series ever produced? In terms of technological advance, in terms of money-earning capacity, in terms of its effect on end-product design and in terms of its effect on the evolution of semiconductor logic. So what do you think was the best series of logic ICs ever made?
Surely you mean 4000-series CMOS logic as the 5th entry?
Andrew you are absolutely right of course. Apologies for the slip. I'm travelling at the moment and ca't acess the entry to change it but I'll ask them back at base to do this. Thanks for pointing it out.
I wanted to vote for the 74HC series; it had the same pin-out and functionality as the (at the time) well-known 74-series, but with much improved gate fan-out and much lower current consumption. Also speed was fast enough - not out and out fast like ECL, and then the later AC (and with all the switching noise and ground-bounce issues that entailed) but fast **enough** for most tasks at the time. So I cast my vote into "other", but I sure would have liked to see separate categories for the CMOS logic based implementations of the 74 TTL logic functions. cheers,
Thanks Fabio that's an idea for another poll
It's gotta be 4000 series for me, 74series grew from RTL and DTL but 4000 was the first CMOS family and made possible all sorts of micro-power applications unthinkable before. It was revolutionary. By showing what could be done with zero quiescent power and freed from the tyranny of the 5volt power rail it got people to use logic outside of traditional "computer" circuits.
Thanks Chris, that's an excellent point
Not forgetting that the 4000 series would run from 3.5V (just) up to 18V, very handy for linear and mixed signal apps, not to mention some of the really exotic MSI functions - huge counters, multifunction gates, PLL, crossbar switches, CMOS transistor arrays, high voltage open collector gates, memories even. No heavy duty silicon compilers needed either.
Most of them you could (can) run at 180'C day in and day out. I know because we did.
A dream technology, the 4000 series was responsible for an awful lot of innovation and lives on in the HC series (albeit without the supply flexibility).
For me I wanted to 74HCT - but plumped for 74 as the closest. The question asked about "money-earning capacity" and "effect on the evolution of semiconductor logic". 74HCT made possible the power reduction of many designs and its rich range of functions made smaller projects possible when CPLDs were relatively expensive.
These days I'd avoid discrete logic like the plague, but I still remember an occasion when my supervisor over-ruled me in a project with discrete logic because I couldn't get to grips with CPLDs quickly enough. It was cheaper too. What do students learn these days? I think they should all learn CPLDs/FPGAs, but the historical importance of discrete families shouldn't be forgotten.
I think the 74LCX series is quite good, mainly because it has 5V tolerance on both inputs *and* outputs, i.e. no substrate diodes on either. This means easy interfacing between logic levels and the ability to power down sections without leakage current spoiling things.