Logic chips are integrated circuits that perform the logic functions AND, OR, XOR, NAND, and NOR. They are common in older electronic devices, since more advanced ICs have replaced the need for individual logic chips in most circuits. But before microcontrollers, logic chips were essential components in complex electronic circuits. They were integral to building the electronic systems on early spaceships like the Gemini and the Space Shuttle.
Microcontrollers are all the rage today, but for some projects a microcontroller might be overkill. If your circuit design goals could be achieved with a simple logic chip that makes the device smaller and lower power, why not?
Types of Digital Logic
Logic signals are expressed as 1’s and 0’s, high and low, or true and false.
Shown below are the schematic symbols and truth tables of the common electronic logic gates:
| Logic gate | Schematic symbol | Truth table |
| AND |  |  |
| OR |  |  |
| NAND |  |  |
| NOR |  |  |
| XOR |  |  |
Logic Chips
The chips below (all from Texas Instruments) will perform the logic functions explained above.
- AND gate: SN74HCS09
- OR gate: SN74HCS4075
- NAND gate: SN74HCS03
- NOR gate: SN74HCS27
- XOR gate: SN74HCS86
Hope you found this quick introduction to logic chips helpful in understanding the different types of logic gates that can be used in a circuit! Leave a comment below if you have any questions.
