I need a replacement IC for an MC680P---it's just a hex inverter, but with a healthy output drive capability---30 mA, according to the datasheet. The original appears to be unobtanium. Any suggestions? I looked at a CD4049, but it lacks the output drive current.
30mA is the absolute maximum rating, not the rated output current drive capability,
which I suspect is standard TTL 10-fold fanout. This family seems to be TTL compatible but with higher noise thresholds (probably partly because they are very slow).
74HCT14 inverter might be a possible replacement, check the pinout.
which I suspect is standard TTL 10-fold fanout. This family seems to be TTL compatible but with higher noise thresholds (probably partly because they are very slow).
74HCT14 inverter might be a possible replacement, check the pinout.
I don't think so, as the normal supply voltage is 15 V +/- 1 V. Couple of stacked HEF4049's maybe, depending on how much drive current is really needed?
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Yeah, looking more carefully, I don't think it really needs that much drive---it's just driving the base of a 2N2222. I originally thought that they used the MC680P because of the higher drive than a 7404; but now I see that it's more likely what Marcel said---it's operating on a 15 volt supply. So maybe the CD4049 WILL work.
Yes, indeed. It's a pity that the 40106 isn't a buffer like the 4049, so it really can only deliver a few milliamps (6.8 mA typ. at 15 V when the output is 1.5 V from the rails).
I think I'll be OK, though, because it is just used to turn on a 2N2222, and THAT sinks the current.