Alt-BEAM Archive

Message #09628



To: beam@sgiblab.sgi.com
From: "Dane Gardner" dane@foremostspring.com
Date: Sat, 29 Jan 2000 21:52:27 -0800
Subject: [alt-beam] Re: Electronic Nomenclature question



content-transfer-encoding: quoted-printable

Can anyone tell me some general guidelines (like the above)
for figuring out what a chip does by its number?


Sure, here's my notes for a test I had a couple of semesters ago.

74 (usually) means that it is a commercial chip. As opposed to the militar=
y 54 series. The 54's are WAY more expensive and are not worth it. The di=
fference? The military chips have a broader power rating, they can handle =
extreme temperatures (high and low), and aren't supposed to be as static se=
nsative as the 74's. Then there's the old 4000 series that is just a low s=
peed CMOS. And the BiCMOS that combines CMOS and TTL (not comatabilities, =
but actual technology within the chip itself).

There are a whole bunch of other chip styles...but I've only run accross th=
em once or twice in ten years now, so don't worry to much about them. =


The real difference between CMOS and TTL is in performance. Like propagati=
on delay (switching speed), noise immunity, power disipation, static sensat=
ivity, etc. A lot of the more advanced TTL is faster, but SUCKS down the p=
ower (the S series wasn't even worth it unless it was plugged into a wall).=
In these notes, I generally went from oldest to newest tech, which usuall=
y means that its slow to fastest.

Complementary Metal-Oxide Semiconductor (CMOS) circuits are generally imple=
mented with a type of Field-Effect Transistor. Some of their flavors are a=
s follows:

5V Series:
HC -- High speed CMOS
HCT -- High speed CMOS with TTL compatability
AC -- Advanced CMOS
ACT -- Advanced CMOS with TTL compatability
AHC -- Advanced High speed CMOS
AHCT -- Advanced High speed CMOS with TTL compatability

3.3V Series:
LV -- Low Voltage CMOS
LVC -- Low Voltage CMOS (same as above, just a next generation)
ALVC -- Advanced Low Voltage CMOS

BiCMOS:
BCT -- BiCMOS
ABT -- Advanced BiCMOS
LVT -- Low Voltage BiCMOS
ALB -- Advanced Low Voltage BiCMOS

Transistor-Transistor Logic (TTL) is implemented with bipolar junction tran=
sistors. Some TTL series packages:

74 or 54 no letters -- straight TTL
S -- Schottky TTL
AS -- Advanced Schottky TTL
LS -- Low power Schottky TTL
ALS -- Advanced Low power Schottky TTL
F -- Fast TTL

"It is my belief that nearly any invented quotation, played with conf=
idence, stands a good chance to deceive." -- Samuel Clemens (Mark Twain)

Insomniac's Dream
Robotics -- Electrical Engineering -- Home Brewing -- And More =

=





content-transfer-encoding: quoted-printable



>
x; PADDING-LEFT: 5px; PADDING-RIGHT: 0px">Can =

anyone tell me some general guidelines (like the above)
for figuring o=
ut =

what a chip does by its number?

 

Sure, here's my notes for a test I had a couple of semesters ago. >
 

74 (usually) means that it is a commercial chip.  As opposed to t=
he =

military 54 series.  The 54's are WAY more expensive and are not worth=
=

it.  The difference?  The military chips have a broader power rat=
ing, =

they can handle extreme temperatures (high and low), and aren't supposed to=
be =

as static sensative as the 74's.  Then there's the old 4000 series tha=
t is =

just a low speed CMOS.  And the BiCMOS that combines CMOS and TTL (not=
=

comatabilities, but actual technology within the chip itself).

 

There are a whole bunch of other chip styles...but I've only run accro=
ss =

them once or twice in ten years now, so don't worry to much about them.&nbs=
p; =


 

The real difference between CMOS and TTL is in performance. =
Like =

propagation delay (switching speed), noise immunity, power disipation, stat=
ic =

sensativity, etc.  A lot of the more advanced TTL is faster, but SUCKS=
down =

the power (the S series wasn't even worth it unless it was plugged into a =

wall).  In these notes, I generally went from oldest to newest tech, w=
hich =

usually means that its slow to fastest.

 

Complementary Metal-Oxide Semiconductor (CMOS) circuits are generally =

implemented with a type of Field-Effect Transistor.  Some of their fla=
vors =

are as follows:

 

5V Series:

HC -- High speed CMOS

HCT -- High speed CMOS with TTL compatability

AC -- Advanced CMOS

ACT -- Advanced CMOS with TTL compatability

AHC -- Advanced High speed CMOS

AHCT -- Advanced High speed CMOS with TTL compatability

 

3.3V Series:

LV -- Low Voltage CMOS

LVC -- Low Voltage CMOS (same as above, just a next generation)

ALVC -- Advanced Low Voltage CMOS

 

BiCMOS:

BCT -- BiCMOS

ABT -- Advanced BiCMOS

LVT -- Low Voltage BiCMOS

ALB -- Advanced Low Voltage BiCMOS

 

Transistor-Transistor Logic (TTL) is implemented with bipolar junction=
=

transistors.  Some TTL series packages:

 

74 or 54 no letters -- straight TTL

S -- Schottky TTL

AS -- Advanced Schottky TTL

LS -- Low power Schottky TTL

ALS -- Advanced Low power Schottky TTL

F -- Fast TTL

 







"It is my belief that nearly any invented =

quotation, played with confidence, stands a good chance to deceive." =

-- Samuel Clemens (Mark Twain) >

Insomniac'=">http://people.we.mediaone.net/krazynemesis/">Insomniac'=
s =

Dream
Robotics -- Electrical Engineering=
-- =

Home Brewing -- And More =





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