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Wht is 7400 series and 741 ?

W

WAZ

Jan 1, 1970
0
In exame my sir asked me why in logic gates IC no. Starts with 74 , not
12 or 23 or somthing like that? Plese give me answer.
NAND 7400
And in Op-Amp why it is 741? plesae tell me.
 
J

John Popelish

Jan 1, 1970
0
WAZ said:
In exame my sir asked me why in logic gates IC no. Starts with 74 , not
12 or 23 or somthing like that? Plese give me answer.
NAND 7400
And in Op-Amp why it is 741? plesae tell me.
The logic that starts with the number 74 are all parts in the TTL
(transistor-transistor-logic) family, that have compatible input and
output signals. This family is further subdivided into groups, based
on improvements in chip technology that either lowered the supply
current or increased the speed, or both. The 74L family uses less
current. The 74S series uses more current, but is much faster,
because of the addition of Schottky diode feedback that prevents
transistor saturation. The 74LS family is a compromise that uses the
Schottky diodes but lowered the supply current. The 74F series was a
much faster chip process, etc.

The opamp named 741 just got a number that was an arbitrary choice,
and has nothing to do with the 74 logic family.
 
J

John Popelish

Jan 1, 1970
0
WAZ said:
In exame my sir asked me why in logic gates IC no. Starts with 74 , not
12 or 23 or somthing like that? Plese give me answer.
NAND 7400
And in Op-Amp why it is 741? plesae tell me.
It just occurred to me, I have no idea where either the 7400 series
came from, or where the 700 series of analog numbers came from, but
here is a better history of TTL logic than I gave, if you are interested.
http://en.wikipedia.org/wiki/7400_series
 
John said:
It just occurred to me, I have no idea where either the 7400 series
came from, or where the 700 series of analog numbers came from,

If I recall correctly, the 74xx was Texas Instruments designation for
their commerical-grade TTL. They also had a parallel 54xx sereies for
their MIL-spec parts.

The µA7xx series came from Farichild. Some other memorable members of
this family were the µA702 and µA709 op-amps, µA711 comparator,
µA739 dual preamp, µA747 (dual µA741 in a single package). µA741
was just the next one in the series.
 
J

John Popelish

Jan 1, 1970
0
If I recall correctly, the 74xx was Texas Instruments designation for
their commerical-grade TTL. They also had a parallel 54xx sereies for
their MIL-spec parts.

But why did they select 74 and 54 for these purposes? That is
essentially the crux of the original question. I think the answer is
something like that your parents used in selecting your name.
The µA7xx series came from Farichild. Some other memorable members of
this family were the µA702 and µA709 op-amps, µA711 comparator,
µA739 dual preamp, µA747 (dual µA741 in a single package). µA741
was just the next one in the series.

Now, tell me who decided uA7xx would be the series designation and why
they made this choice.
 
John said:
I think the answer is
something like that your parents used in selecting your name.

I think this is pretty close to correct. Those were probably just the
next blocks of numbers not being used by that company. Other companies
had logic families (such as RTL and DTL) that are now forgotten. Other
companies had TTL logic with other numbering systems. The 74xx
nomeclature survived because of the poplarity of TI's TTL series.
Eventually, even CMOS gave up most of its own numbering system and
pinouts and was assimilated.

With the possible exceptions of the LM309 and LM317, who remembers the
linear regulators that competed with the 78xx and 79xx sereis? In this
case, I think that the descriptive way the numbers were assigned to the
78xx, plus the range of popular values, led to the dominance of this
series and its offspring (the 79xx seiies obviously qualifes as
offspring).
 
W

WAZ

Jan 1, 1970
0
thnks every body for answering.,
As you told john 74XX is for commercial purpose. And 54XX is for
military application.
Device in 74XX series works over a temprature range 0 to 70'C and over
supply range 4.75V to 5.25 Volts. And in

54XX series it works on Temp range -55 to 125'C and Supply range 4.5V
to 5.5Volts.
I think that answer is in its Ranges . like for 74XX series first
digit(not 0 ,but 7) of temp range and first digit of

voltage range (4) makes 74. and similiarly for 54XX series first digit
for temp is 5 and first digit for Vol. is 4.

I think(not sure) this could be answer of my question .Wht do you
think?

Wazim Shaikh
 
J

John Popelish

Jan 1, 1970
0
WAZ said:
thnks every body for answering.,
As you told john 74XX is for commercial purpose. And 54XX is for
military application.
Device in 74XX series works over a temprature range 0 to 70'C and over
supply range 4.75V to 5.25 Volts. And in

54XX series it works on Temp range -55 to 125'C and Supply range 4.5V
to 5.5Volts.
I think that answer is in its Ranges . like for 74XX series first
digit(not 0 ,but 7) of temp range and first digit of

voltage range (4) makes 74. and similiarly for 54XX series first digit
for temp is 5 and first digit for Vol. is 4.

I think(not sure) this could be answer of my question .Wht do you
think?

Random numerical coincidences do not usually capture reality. If they
did, numerology would be science. By the way, there was a short lived
64 series that covered the industrial temperature range -25 to +85 C).
How does your hypothesis account for this?

I think the real answer came out of some marketing meeting, where they
looked at what numbers were already taken for similar things and tried
out how new numbers sounded. In other words, it was a totally
arbitrary choice that means nothing.
 
P

prateek

Jan 1, 1970
0
74XXX series stands for LSI TTL chips. 8XXX is for MSI, TTL chips.

prateek
 
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