Dictionary of Electronic Terms
"A"
"B"
"C",
"D",
"E",
"F",
"G",
"H",
"I",
"J",
"K",
"L",
"M",
"N",
"O",
"P",
"Q",
"R",
"S",
"T",
"U",
"V",
"W",
"X",
"Y",
"Z"
IC 7405 Hex Inverter, with Open Collector
The logic diagram of this type does not show the Open Collector function.
 7405 Hex Inverter | A connection diagram of a 7405 TTL Hex Inverter with Open Collector outputs. This version and other similar versions [74LS05] are available in one of three different 14-pin packages; A Plastic DIP [PDIP], a Small Outline Package [SOP] or a Small Outline IC [SOIC]. This diagram happen to only show the functions, but the graphic below shows a possible pinout. The power and ground pins are almost never shown in these types of diagrams. Just keep in mind that many of these TTL devices have an alternate pin-out. Although it seems that the secondary pin out seemed to be seldom used, but it's something to keep in mind. |
Hex Inverter Chip. An inverter chip inverts the input signal [Truth Table], and a hex inverter has six individual inverters contained within the same package. A buffer has a higher output drive than a non-buffered IC. An inverter may have an Open Collector output, which is an IC with a collector on the final transistor output stage that is not tied to Vcc, or left open, and requires a Pull-up Resistor. However other inverter devices may have normal Totem-Pole Outputs and not require a resistor.
Hex Drivers by Function:
7404; Hex Inverter / Buffer
7405; Hex Inverter with Open Collector Outputs
7405; Hex Inverter with Open Collector, High Voltage Outputs
7407; Hex Buffer with Open Collector Outputs
7414; Hex Inverter with Schmitt Trigger Inputs
4069; CMOS Hex Inverter [non-TTL I/O]
74xx represents the commercial temperature range and 54xx series represents the military temperature range [IC Temperature Prefixes], or really the extended temperature range. |  Schmitt Trigger |
Only the base [74xx] TTL family is shown as an example. However the 74xx family is obsolete in favor of any number of other sub-families, for example; 54AC04, 54AC05, 54HC04, 54ACT05, which may still be in production. Refer to a list of possible TTL Logic Families.
Only the 7400 series is shown above, but the pinout and many of the packages are the same as the military grade 5400 series. However a 74xx may be plastic while the 54xx might use a ceramic package [all with the same pinout as the 74xx device shown].
Note there are many ICs that have either buffered outputs or open collector outputs which are not shown here. The list is for Hex Inverters.
Logic Gate Manufacturers, by logic family.
54ACT04 Semiconductor Die Graphic
The 54 in the part number signifies a military component with an operational temperature range of -55C to +125C.
The ACT means Advanced CMOS with TTL compatible inputs. A CMOS device that works with TTL levels.
The '04' is the function of the part; a standard Hex Inverter.
A '74' instead of a '54' would indicate a commercial operating range of 0C to +70C.
At any rate; the graphic to the right shows a chip die for a 54ACT04. The function of each pin number is shown within the graphic.
Note the large number of ground pins [VSS] compared to the two power pins [VDD]. Also note how the pin functions are inter-mixed, so that the inputs [Y pins] are next to the output pins [A pins].
