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| HEF CMOS IC is NLA--what to use? |
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| iXod:
A 25-year-old relay switching circuit (6 inputs driving 6 relays) includes a HEF4023BP: triple, 3-input AND gates. Now kaput, it needs to be replaced. This IC has not been available for some time. I can find no supplies (other than eBay which for obvious reasons I'd like to avoid). What CMOS family can provide this modest performance? The circuit is neither fast (switching relays a few times a minute) nor quick (fast relay activation is not a requirement). I don't know what makes HEF CMOS unique, so I don't know for what feature the designers chose this CMOS family. (Trying to educate myself, Google wouldn't return any useable search results for the HEF family.) Replacement suggestions welcome. And a clue to what HEF is all about. Thanks. |
| oPossum:
CD4023 should work in place of the HEF4023. They are readily available. https://www.findchips.com/search/cd4023 |
| Ian.M:
HEF is just Philips (now NXP)'s prefix for 4000 series CMOS logic. Simply substitute any other brand of 4000 series 4023 still available from major distributors. @oPossum: You beat me to it! :-+ |
| oPossum:
Looks like the On Semi (Motorola) is also still available. https://www.findchips.com/search/mc14023 |
| Gyro:
HEF tended to be faster than the other 4000 series manufacturers (used to be handy if your address decode logic didn't quite make it :D), but I doubt that would be an issue for a relay switching unit. |
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