comparators in IC 555 REPOST

Background - until 3 weeks ago I knew absolutely NOTHING about
electronics, and even now I know very little. So I'm just starting
out! Some of the responses to my origiinal post were helpful, but I
still haven't been able to 'name' the comparators in the 555. All of
the diagrams just seem to say 'comparator 1' or 'comparator 2'. Those
that suggest I look at the data sheet are assuming I would know one
end of a data sheet from the other.

New question: are the comparators in the 555 both 741s. If not, what
'number' is given to them, if at all? Maybe they don't have a number.
Maybe the the only place you find these particular types of comparator
are in the 555 in which case my question doesn't have the kind of
answer I seek!
As a for instance, say you were in a pub and someone said, 'The
comaprators in the 555 are 741s, aren't they.?' You would reply, No
they're not, they're 631s (or 456s or 2134s or whatever they are).
This is not a homework question! It's just a curiosity question.
Thanks!

 

[John Fields]

On Mon, 13 Aug 2012 09:46:31 -0700 (PDT), macmanus130@btinternet.com
wrote:

Background - until 3 weeks ago I knew absolutely NOTHING about
electronics, and even now I know very little. So I'm just starting
out! Some of the responses to my origiinal post were helpful, but I
still haven't been able to 'name' the comparators in the 555. All of
the diagrams just seem to say 'comparator 1' or 'comparator 2'. Those
that suggest I look at the data sheet are assuming I would know one
end of a data sheet from the other.

New question: are the comparators in the 555 both 741s. If not, what
'number' is given to them, if at all? Maybe they don't have a number.
Maybe the the only place you find these particular types of comparator
are in the 555 in which case my question doesn't have the kind of
answer I seek!
As a for instance, say you were in a pub and someone said, 'The
comaprators in the 555 are 741s, aren't they.?' You would reply, No
they're not, they're 631s (or 456s or 2134s or whatever they are).
This is not a homework question! It's just a curiosity question.
Thanks!

---
The comparators in a 555 are not commercially available models which
are assembled with other components to make a 555.

A 555 is an integrated circuit with all of the circuit elements and
connections fabricated from/on a tiny slice of silicon.

http://en.wikipedia.org/wiki/Semiconductor_device_fabrication


--
JF

 

[fungus]

On Monday, August 13, 2012 6:46:31 PM UTC+2, (unknown) wrote:

Background - until 3 weeks ago I knew absolutely NOTHING about

electronics, and even now I know very little. So I'm just starting

out! Some of the responses to my origiinal post were helpful, but I

still haven't been able to 'name' the comparators in the 555. All of

the diagrams just seem to say 'comparator 1' or 'comparator 2'. Those

that suggest I look at the data sheet are assuming I would know one

end of a data sheet from the other.



New question: are the comparators in the 555 both 741s. If not, what

'number' is given to them, if at all? Maybe they don't have a number.

Maybe the the only place you find these particular types of comparator

are in the 555 in which case my question doesn't have the kind of

answer I seek!

As a for instance, say you were in a pub and someone said, 'The

comaprators in the 555 are 741s, aren't they.?' You would reply, No

they're not, they're 631s (or 456s or 2134s or whatever they are).

This is not a homework question! It's just a curiosity question.

There a thousands of variants of the 555,
made by every manufacturer imaginable. Any
one of them can have different components
internally so long as the pinout doesn't
change. There's low power variants, military
variants...etc.

There's a big list on the wikipedia page
I posted last time.

https://en.wikipedia.org/wiki/555_timer_IC



Some are low power.

 

Thanks fungus! Now it makes better sense what's going on.

 

On Monday, 13 August 2012 17:46:31 UTC+1, (unknown) wrote:

Background - until 3 weeks ago I knew absolutely NOTHING about electronics, and even now I know very little. So I'm just starting out! Some of the responses to my origiinal post were helpful, but I still haven't been able to 'name' the comparators in the 555. All of the diagrams just seem to say 'comparator 1' or 'comparator 2'. Those that suggest I look at the data sheet are assuming I would know one end of a data sheet from the other. New question: are the comparators in the 555 both 741s. If not, what 'number' is given to them, if at all? Maybe they don't have a number. Maybe the the only place you find these particular types of comparator are in the 555 in which case my question doesn't have the kind of answer I seek! As a for instance, say you were in a pub and someone said, 'The comaprators in the 555 are 741s, aren't they.?' You would reply, No they're not, they're 631s (or 456s or 2134s or whatever they are). This is not a homework question! It's just a curiosity question. Thanks!

Thanks fungus, now it makes a bit more sense!

 

[m II]

On 12-08-13 10:46 AM, macmanus130@btinternet.com wrote:

Background - until 3 weeks ago I knew absolutely NOTHING about
electronics, and even now I know very little. So I'm just starting
out! Some of the responses to my origiinal post were helpful, but I
still haven't been able to 'name' the comparators in the 555. All of
the diagrams just seem to say 'comparator 1' or 'comparator 2'. Those
that suggest I look at the data sheet are assuming I would know one
end of a data sheet from the other.

New question: are the comparators in the 555 both 741s. If not, what
'number' is given to them, if at all? Maybe they don't have a number.
Maybe the the only place you find these particular types of comparator
are in the 555 in which case my question doesn't have the kind of
answer I seek!

There doesn't need to be a name or model number. A comparator is just a
functional block of components. You wouldn't name an amplifier section
or a voltage divider section or an input section unless they were
discrete components, sourced elsewhere.


mike

 

[petrus bitbyter]

<macmanus130@btinternet.com> schreef in bericht
news:538647be-7c5d-446e-ba6f-dd521278c7e2@n13g2000vby.googlegroups.com...

Background - until 3 weeks ago I knew absolutely NOTHING about
electronics, and even now I know very little. So I'm just starting
out! Some of the responses to my origiinal post were helpful, but I
still haven't been able to 'name' the comparators in the 555. All of
the diagrams just seem to say 'comparator 1' or 'comparator 2'. Those
that suggest I look at the data sheet are assuming I would know one
end of a data sheet from the other.

New question: are the comparators in the 555 both 741s. If not, what
'number' is given to them, if at all? Maybe they don't have a number.
Maybe the the only place you find these particular types of comparator
are in the 555 in which case my question doesn't have the kind of
answer I seek!
As a for instance, say you were in a pub and someone said, 'The
comaprators in the 555 are 741s, aren't they.?' You would reply, No
they're not, they're 631s (or 456s or 2134s or whatever they are).
This is not a homework question! It's just a curiosity question.
Thanks!

Well, with this explanation your question makes much more sense. Although
many of us are in electronics for years, no one pretends to be a magician.
Some may have crystal balls but they are always out of order

As for the question, a comparator is not an electronic device but an
electronic circuit. You can build one with devices like transistors, (or
even tubes) resistors and so on. A lot of comparators are designed to be
placed in a chip. You can find components (packages) with up to four (FAIK)
comparators in one chip. They are given a partnumber and called
"comparators" as that are the circuits they contain.

The design of the 555 contains two comparators but only as parts of a more
comprehensive circuit. So they are just the comparators (circuits) inside
the 555 and have no other name or partnumber.

petrus bitbyter

 

[Jon Kirwan]

On Mon, 13 Aug 2012 09:46:31 -0700 (PDT),
macmanus130@btinternet.com wrote:

Background - until 3 weeks ago I knew absolutely NOTHING about
electronics, and even now I know very little. So I'm just starting
out! Some of the responses to my origiinal post were helpful, but I
still haven't been able to 'name' the comparators in the 555. All of
the diagrams just seem to say 'comparator 1' or 'comparator 2'. Those
that suggest I look at the data sheet are assuming I would know one
end of a data sheet from the other.

New question: are the comparators in the 555 both 741s. If not, what
'number' is given to them, if at all? Maybe they don't have a number.
Maybe the the only place you find these particular types of comparator
are in the 555 in which case my question doesn't have the kind of
answer I seek!
As a for instance, say you were in a pub and someone said, 'The
comaprators in the 555 are 741s, aren't they.?' You would reply, No
they're not, they're 631s (or 456s or 2134s or whatever they are).
This is not a homework question! It's just a curiosity question.
Thanks!

Found these:

http://ssihla.files.wordpress.com/2011/02/555.png
http://eliot84.files.wordpress.com/2009/09/ne555-schematic.png
http://www.electronics.dit.ie/staff/mtully/555%20folder/555equiv.gif

Also, LTspice's Yahoo group library includes Jim Thompson's
CMOS version, but I don't think anyone has laid out a nice
looking schematic for it -- just the .subckt model.

Jon

 

[John Larkin]

On Mon, 13 Aug 2012 09:46:31 -0700 (PDT), macmanus130@btinternet.com
wrote:

Background - until 3 weeks ago I knew absolutely NOTHING about
electronics, and even now I know very little. So I'm just starting
out! Some of the responses to my origiinal post were helpful, but I
still haven't been able to 'name' the comparators in the 555. All of
the diagrams just seem to say 'comparator 1' or 'comparator 2'. Those
that suggest I look at the data sheet are assuming I would know one
end of a data sheet from the other.

New question: are the comparators in the 555 both 741s. If not, what
'number' is given to them, if at all? Maybe they don't have a number.
Maybe the the only place you find these particular types of comparator
are in the 555 in which case my question doesn't have the kind of
answer I seek!
As a for instance, say you were in a pub and someone said, 'The
comaprators in the 555 are 741s, aren't they.?' You would reply, No
they're not, they're 631s (or 456s or 2134s or whatever they are).
This is not a homework question! It's just a curiosity question.
Thanks!

This is the almost-correct internal schematic:

http://pcbheaven.com/scripts/imagepresent.php?filename=%2Fwikipages%2Fimages%2F555theory_1237044106.png

All the internal functions are done with NPN and PNP transistors.
Q1...Q8 make one comparator, and Q10...Q15 is the other.


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

 

[Jim Thompson]

On Mon, 13 Aug 2012 20:24:31 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Mon, 13 Aug 2012 09:46:31 -0700 (PDT), macmanus130@btinternet.com
wrote:

Background - until 3 weeks ago I knew absolutely NOTHING about
electronics, and even now I know very little. So I'm just starting
out! Some of the responses to my origiinal post were helpful, but I
still haven't been able to 'name' the comparators in the 555. All of
the diagrams just seem to say 'comparator 1' or 'comparator 2'. Those
that suggest I look at the data sheet are assuming I would know one
end of a data sheet from the other.

New question: are the comparators in the 555 both 741s. If not, what
'number' is given to them, if at all? Maybe they don't have a number.
Maybe the the only place you find these particular types of comparator
are in the 555 in which case my question doesn't have the kind of
answer I seek!
As a for instance, say you were in a pub and someone said, 'The
comaprators in the 555 are 741s, aren't they.?' You would reply, No
they're not, they're 631s (or 456s or 2134s or whatever they are).
This is not a homework question! It's just a curiosity question.
Thanks!

This is the almost-correct internal schematic:

http://pcbheaven.com/scripts/imagepresent.php?filename=%2Fwikipages%2Fimages%2F555theory_1237044106.png

All the internal functions are done with NPN and PNP transistors.
Q1...Q8 make one comparator, and Q10...Q15 is the other.

As I reported 12 hours ago...

Date: Mon, 13 Aug 2012 08:01:05 -0700
Message-ID: <pj5i28ps8fvavrtro3b6p6k2kaj67cmtnh@4ax.com>

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[John Fields]

On Mon, 13 Aug 2012 20:24:31 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

This is the almost-correct internal schematic:

http://pcbheaven.com/scripts/imagepresent.php?filename=%2Fwikipages%2Fimages%2F555theory_1237044106.png

---
The correct one is on page 11-4 of Hans Camenzind's book,
"Designing Analog Chips", which can be downloaded for free at:

www.designinganalogchips.com


--
JF

 

[Fred Abse]

On Mon, 13 Aug 2012 09:46:31 -0700, macmanus130 wrote:

New question: are the comparators in the 555 both 741s. If not, what
'number' is given to them, if at all?

No, they're not. They're made from transistors that form part of the
monolithic silicon slab that is the IC itself.

Your question has no meaning.

LTspice has an "educational", example, circuit, comprising the internals
of the 555. It actually works. Get LTspice (free), and study it.

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

 

[Jasen Betts]

On 2012-08-13, macmanus130@btinternet.com <macmanus130@btinternet.com> wrote:

Background - until 3 weeks ago I knew absolutely NOTHING about

New question: are the comparators in the 555 both 741s. If not, what
'number' is given to them, if at all? Maybe they don't have a number.
Maybe the the only place you find these particular types of comparator
are in the 555 in which case my question doesn't have the kind of
answer I seek!

The functional blocks inside integrated circuits don't have part
numbers, they are just collections of bespoke components,
components that were designed specifically for that application and
also don't have part numbers.

In integrated circuit design it costs no more to use a bespoke part
than it does to use a copy of an existing discrete part.

--
⚂⚃ 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net ---

 

[m II]

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On 12-08-13 04:20 PM, m II wrote:

On 12-08-13 10:46 AM, macmanus130@btinternet.com wrote:

Still at it, eh Maynard? Your counterfeiting of my account is illegal.
You ARE aware of that, no?

mike



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