Are there any such components as a 12 volt NOR gate or similar?
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3 Answers
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Sure you can check out the CD40xx family from TI.
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1\$\begingroup\$ or HEF4000 family (Philips -> NXP) or MC14000 family (Motorola -> OnSemi) \$\endgroup\$Curd– Curd2025-10-14 08:33:32 +00:00Commented yesterday
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\$\begingroup\$ ... or anything known as being a part of the 4000 CMOS logic family. \$\endgroup\$zebonaut– zebonaut2025-10-14 09:45:16 +00:00Commented 23 hours ago
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Go to the Digi Key website, search on "logic", you will be presented with a pictorial array of categories. Only a few of these categories are applicable to your question. Select "Gates and Inverters". (Other categories such as "Flip Flops" might be applicable as well. But the process I describe next will be applicable to the other categories as well.)
When you select Gates & Inverters, you will be presented with a multi-page selection chart (something like 13,000 items). At the top of this chart you will see various parametric selection menus. Find the one labeled "Voltage - Supply". Scroll down this menu until you find the ranges of supply voltages that include 12volts. The first one you will see is "3V - 12V", select this one, and all other entries which include 12 volts - e.g "3v - 15v" - there are about 5 applicable ranges. Be sure to select all that are applicable to your 12 volt requirement. Click on the "APPLY ALL" button. You will be presented with about 800 parts, Select the "In Stock" button on the left of the screen and hit "Apply All" again. This will result in about 400 realistic choices for gates and inverters which fit your 12 V criteria. Amongst them you will find NOR gates, NAND gates, etc. Plenty to choose from.
A few other comments are in order:
A. If you are going to run your circuit on 12 Volts, you should choose devices which are specified a little higher - 15 volts max would be a good choice, Or change your supply voltage if that's an option.
B. If you are planning to use this in a "12 Volt" automotive application, you should be aware that auto electrical systems are NOT 12 volts, more like 15 volts and loaded with voltage spikes that will kill any logic gate connected to the raw "12 Volt" supply lines. How to make this supply voltage "clean" and non-lethal to chips would be a topic for another question.
C. These gates are mostly descendants of the original CMOS "4000 Series" introduced by RCA way back in the 1960's. Now made by the likes of Harris, TI, OnSemi, etc. They can have some odd pinouts, unlike conventional 74xx logic types. Be sure to get a data sheet for each part you select to unveil such oddities. You will also find that many of the 4000 series parts do not follow the 7400 logic naming conventions (e.g. 7400 Nand, 7404 Inverter, etc.) Some exploration will be needed to find the functionality you need.
D. For the most part these devices are "pure CMOS", and not TTL-compatible. So, they have certain characteristics you need to be knowledgeable of to properly apply them to your circuit. Again, the topic for another question.
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3\$\begingroup\$ "They can have some odd pinouts..." or perfectly normal pinouts, depending on your perspective. \$\endgroup\$TimWescott– TimWescott2025-10-13 04:37:40 +00:00Commented 2 days ago
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1\$\begingroup\$ CMOS gates running at 12V are often very sensitive to ESD relative to more modern devices. Touching test lead wires onto powered circuits can often destroy gates. It can sometimes be much more robust to use 3.3v or 5v logic with discrete component level shifters. \$\endgroup\$ocelot– ocelot2025-10-13 08:02:33 +00:00Commented 2 days ago
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\$\begingroup\$ ocelot - Absolutely true! The modern versions are a bit more robust in this regard, but still relatively fragile compared to the 74xx family devices. \$\endgroup\$Woodrow Bonewright– Woodrow Bonewright2025-10-13 10:46:43 +00:00Commented yesterday
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1\$\begingroup\$ Who would use bipolar TTL devices for new designs? Most would use the cmos variants methinks. \$\endgroup\$Kartman– Kartman2025-10-13 13:15:29 +00:00Commented yesterday
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\$\begingroup\$ @ocelot Traditionally, CMOS logic is sensitive to ESD damage, TTL is not. While the *4000 logic family is available as CMOS only, you can use either Bipolar or CMOS technology for families designed for 5 V and below, so these families might also be susceptible to ESD damage. So the answer really is: "It depends". Also, modern CMOS gates often have protective measures at their inputs, which tends to help a lot. There is a great table on p. 7 of TI's Logic Guide, document ID sdyu001ab. \$\endgroup\$zebonaut– zebonaut2025-10-14 09:43:52 +00:00Commented 23 hours ago
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For single logical functions it might be possible to use open collector drivers and connect them using "wired or" style. Some TTL gates had open collector outputs suitable for more than 5 volts (lamp drivers) although the Chip runs on 5 volts. Not useful for pure 12-Volt system however.
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