7400 series integrated circuits ICs

7400 Series integrated circuits (ICs) have a lot of ready to use logic gates and various other circuits within them.

74xx…

  • The number 74 indicates the 7400 series of integrated circuits
  • Then there are usually 2 letters following 74. But there could be more or less. The letters indicate what type of transistors are built into the IC. Which affects a number of electrical properties in ways that you need to be aware of.
    1. HC (High Speed CMOS) is most common now.
    2. LS (Low Power Schottky) used to be the most common.
    3. You will often see “xx” in place of those letters in order to indicate that no specific kind is being referred to at that time.



74HCxx ICs kit. An Amazon affiliate link ad that supports this site.

High Speed CMOS (74HCxx) is the standard variation of the 7400 series ICs to learn about and use these days. Often they can replace a 74LSxx ICs in the same circuits. Whereas the 74LSxx ICs usually can not be used to replace a 74HCxx IC.  


74LSxx ICs kit for those who want to experiment with older technology. An affiliate link ad that supports this site.

  • After those 2 letters, there is another 2 or 3 digit number that is used to indicate what circuit(s) are build in to the IC.
    1. 74xx00 is a quad 2 input NAND gate.
    2. 74xx14 is a Hex inverters with Schmitt trigger inputs IC.
  • 54xxxx instead of 74xxxx indicates that it is built to military specifications. You will often see 5400 series ICs explained on the same datasheet as the 7400 series component.

Letter(s) added before the part number often indicates the manufacturer and has nothing to do with the operation of the IC. Nothing stops a different manufacturer from adding the same letters. So the letters before 74xxXX is not necessarily a guarantee of who made the IC.

  • SN74xxxx – Texas Instruments (TI).
  • M74xxxx – STMicroelectronics.
  • MC74xxxx – On semiconductor.
  • DM74xxxx – Fairchild Semiconductors.

Examples:

Numbers obtained from Texas Instrument datasheets. TI starts off their 7400 series IC with SN. Other manufactures probably start of the the same component with different letters, but the component itself is probably made to the same specifications.

Warning! Datasheets often include multiple versions of a component. Make sure each specification you are looking at is for your specific component. I may accidently post the wrong specs from time to time. Always consult the actual datasheet itself.

Quad 2 input (positive) NAND gate:

  1. SN7400 – original version of the integrated circuit.
    • Absolute max. supply voltage = 7V
    • Absolute max. input voltage = 5.5V
    • Recommended supply voltage = Min. 4.75V – Max. 5.25V
    • High level input voltage = 2V Min
    • TTL logic outputs
    • High level output current = Not given on datasheet
    • Low level output current = Max 16mA
  2. SN74LS00  Quad 2 Input Positive NAND Gate – Low power Schottky version of the integrated circuit.
    • Absolute max. supply voltage = 7V
    • Absolute max. input voltage = 7V
    • Recommended supply voltage = Min. 4.75V – Max. 5.25V
    • High level input voltage = Min 2V
    • TTL logic outputs
    • High level output current = Max -0.4mA
    • Low level output current = Max 4mA
  3. SN74HC00 – High speed CMOS version of the integrated circuit.
    • Absolute max. supply voltage = 7V
    • Recommended supply voltage = Min. 2V – NOM. 5V – Max. 6V
    • Continuous output current = ±25mA
    • Continuous current through Vcc or GND = ±50mA
    • High level input (depends on Vcc voltage)
      • Vcc = 2V – Min. 1.5V
      • Vcc = 4.5V – Min. 3.15V
      • Vcc = 6V – Min. 4.2V
    • Low level input (depends on Vcc voltage)
      • Vcc = 2V – Max. 0.5V
      • Vcc = 4.5V – Max. 1.35V
      • Vcc = 6V – Max. 1.8

Fan out: how many 74LSxx inputs can be driven by an output.

This is a new page that will be updated soon!