EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: LinuxHata on November 18, 2023, 09:01:36 am
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Hello.
There are 4 NAND, 4 OR, 6 Inverter logic ICs in a single physical package, but are there any ic, that have more than 4 logical elements in it?
For example, I'm looking a chip which will have 8 or separate NAND or AND gate in it. (I'm not looking for a 8 input NAND gate, I need 8 separate gates with own input and output).
I need this for ease of soldering and assembly.
I know that any MCU can be programmed for that, but I'm looking for an existing hardware solution.
Thanks!
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How about a 16V8? 20V10?
Do you have a schematic of your proposed logic circuit?
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Short answer, no.
If you need more logic gates (not 'elements'), there are CPLD (Complex Programmable Logic Device) and FPGA (Field-Programmable Gate Array). Not as easy to use as the discrete logic gates are.
Another trick is to use a memory as a LUT (Look Up Table), in order to implement logic functions with CLC (Combinational Logic Circuit). The address bus of the memory plays the role of the logic inputs, and the data out lines are the outputs. So 8 logic functions at once for a typical 8 bits/byte memory chip.
If it's for learning, I'll stick with logic gates first, to get a grasp of how things works at the lower levels. Implement a few types of FF (Flip-Flops), some counters, maybe an adder. Of course, none of these will give any goose bumps to students. Then move to FPGA for more spectacular applications, in a second course of Digital Design II. For FPGA practice there are ready made devboards, which will require no soldering and no breadboarding, only a computer to load the desired bitstream.
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Thanks, I know about FPGA, CPLD and PLAs.
I asked whenever there were 8 or more logic gates in one physical package.
Since there are none, I'll find a different solution.
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74xx244/245, octal bus drivers. 74xx373/374 octal DQ flip-flop (but sharing clock). Even ULN2803, octal relay driver. 74LVC16244/245 16 way bus drivers, 74LVC16373/374 16-bit D-Q flip-flop.
OK most of those aren't really individual gates, but the 16-way chips are handy for datapaths
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Those extended capability devices exist but require more pins and you begin to see the unusual packages like 'DIP-24 narrow' .300" or some of the DIP-48 .600" packages. We see extended pin counts for things like 1KB and 2KB Dual Port Ram and some uncommon latch / flip-flop devices. IF there is a need with quantity involved anything is possible. Look at some of the unusual analog DIP-16 .300" packages with a heatsink tab sticking out the end, usually a power amplifier device. Sadly those unusual specialty devices become obsolete quickly!! Some body somewhere has 10,000 in stock and they never seem to connect with the five or ten people who only need one!