Comparator with driver output...

[Fred Bloggs]

On Saturday, November 19, 2022 at 2:34:34 AM UTC-5, Ricky wrote:

On Friday, November 18, 2022 at 9:15:53 PM UTC-5, Fred Bloggs wrote:
On Thursday, November 17, 2022 at 3:20:08 PM UTC-5, sonnic...@gmail.com wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a open-collector output.
Does the group know about comparators with driver output, hence can pull up and down, and output like an ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could balance itself
You could use an op amp to buffer the LM393 OC output. Two cheap parts are still cheap. The super fast comparators mentioned are all very fussy about layout and have self-oscillation problems if you\'re not careful about every little thing.
No part is cheap if it takes up space on a crowded board.

Many Greenpak devices have comparators in them, but few have opamps.

I just want to say I am so thankful to have you around to set me straight. Well, my word, what could I do without you.

WTF you think a part like this just might be for?

https://www.ti.com/lit/ds/symlink/lm392-n.pdf

--

Rick C.

+- Get 1,000 miles of free Supercharging
+- Tesla referral code - https://ts.la/richard11209

 

[Ricky]

On Saturday, November 19, 2022 at 6:04:05 AM UTC-5, Fred Bloggs wrote:

On Saturday, November 19, 2022 at 2:34:34 AM UTC-5, Ricky wrote:
On Friday, November 18, 2022 at 9:15:53 PM UTC-5, Fred Bloggs wrote:
On Thursday, November 17, 2022 at 3:20:08 PM UTC-5, sonnic...@gmail.com wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a open-collector output.
Does the group know about comparators with driver output, hence can pull up and down, and output like an ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could balance itself
You could use an op amp to buffer the LM393 OC output. Two cheap parts are still cheap. The super fast comparators mentioned are all very fussy about layout and have self-oscillation problems if you\'re not careful about every little thing.
No part is cheap if it takes up space on a crowded board.

Many Greenpak devices have comparators in them, but few have opamps.
I just want to say I am so thankful to have you around to set me straight. Well, my word, what could I do without you.

WTF you think a part like this just might be for?

https://www.ti.com/lit/ds/symlink/lm392-n.pdf

What are you talking about???

I like that you picked a part that comes in tiny packages, like DIPs. Even the SOIC is a large package these days.

Figure 1. SOIC and PDIP Packages

WTF is going on with you? An opamp and a comparator is always going be a larger package than a simple comparator that does the job.

--

Rick C.

++ Get 1,000 miles of free Supercharging
++ Tesla referral code - https://ts.la/richard11209

 

[John Larkin]

On Sat, 19 Nov 2022 03:04:01 -0800 (PST), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:

On Saturday, November 19, 2022 at 2:34:34 AM UTC-5, Ricky wrote:
On Friday, November 18, 2022 at 9:15:53 PM UTC-5, Fred Bloggs wrote:
On Thursday, November 17, 2022 at 3:20:08 PM UTC-5, sonnic...@gmail.com wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a open-collector output.
Does the group know about comparators with driver output, hence can pull up and down, and output like an ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could balance itself
You could use an op amp to buffer the LM393 OC output. Two cheap parts are still cheap. The super fast comparators mentioned are all very fussy about layout and have self-oscillation problems if you\'re not careful about every little thing.
No part is cheap if it takes up space on a crowded board.

Many Greenpak devices have comparators in them, but few have opamps.

I just want to say I am so thankful to have you around to set me straight. Well, my word, what could I do without you.

WTF you think a part like this just might be for?

https://www.ti.com/lit/ds/symlink/lm392-n.pdf

Beware note 5!

 

[Robert Latest]

sonnic...@gmail.com wrote:

Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a open-collector
output. Does the group know about comparators with driver output, hence can
pull up and down, and output like an ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could balance
itself

What do you mean with \"could balance itself?\"

I once needed to drive a cheap, slow 24V H-bridge using a logic output. I ended
up using an LM324, with two pairs of paralleled amps wired as comparators for
more drive capability. Probably the only thing I ever used an 324 for.

 

[Fred Bloggs]

On Saturday, November 19, 2022 at 12:03:50 PM UTC-5, Ricky wrote:

On Saturday, November 19, 2022 at 6:04:05 AM UTC-5, Fred Bloggs wrote:
On Saturday, November 19, 2022 at 2:34:34 AM UTC-5, Ricky wrote:
On Friday, November 18, 2022 at 9:15:53 PM UTC-5, Fred Bloggs wrote:
On Thursday, November 17, 2022 at 3:20:08 PM UTC-5, sonnic...@gmail.com wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a open-collector output.
Does the group know about comparators with driver output, hence can pull up and down, and output like an ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could balance itself
You could use an op amp to buffer the LM393 OC output. Two cheap parts are still cheap. The super fast comparators mentioned are all very fussy about layout and have self-oscillation problems if you\'re not careful about every little thing.
No part is cheap if it takes up space on a crowded board.

Many Greenpak devices have comparators in them, but few have opamps.
I just want to say I am so thankful to have you around to set me straight. Well, my word, what could I do without you.

WTF you think a part like this just might be for?

https://www.ti.com/lit/ds/symlink/lm392-n.pdf
What are you talking about???

I like that you picked a part that comes in tiny packages, like DIPs. Even the SOIC is a large package these days.

Figure 1. SOIC and PDIP Packages

WTF is going on with you? An opamp and a comparator is always going be a larger package than a simple comparator that does the job.

--

Rick C.

++ Get 1,000 miles of free Supercharging
++ Tesla referral code - https://ts.la/richard11209

https://vendor.ultralibrarian.com/TI/embedded/?gpn=LM392&package=DGK&pin=8&sid=&c=1

https://www.ti.com/lit/ml/mpds028d/mpds028d.pdf?ts=1668889533066&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FLM392

Dimensions mm, multiply by 0.04 ( or 0.039) to convert to inches.

3.00mm longest dimension looks pretty small to me.

Lots of very delicate precision applications here:

https://www.ti.com/lit/an/snoa667b/snoa667b.pdf?ts=1668889907980&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FLM392

There\'s plenty of stock out there. Seems a bit pricey at $1.50- not sure if that\'s another \"supply chain\" issue or it was always that way. Price is slow to come down in quantity. Makes no difference to a \"one-off\" project.

 

[Fred Bloggs]

On Saturday, November 19, 2022 at 12:15:47 PM UTC-5, John Larkin wrote:

On Sat, 19 Nov 2022 03:04:01 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

On Saturday, November 19, 2022 at 2:34:34 AM UTC-5, Ricky wrote:
On Friday, November 18, 2022 at 9:15:53 PM UTC-5, Fred Bloggs wrote:
On Thursday, November 17, 2022 at 3:20:08 PM UTC-5, sonnic...@gmail.com wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a open-collector output.
Does the group know about comparators with driver output, hence can pull up and down, and output like an ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could balance itself
You could use an op amp to buffer the LM393 OC output. Two cheap parts are still cheap. The super fast comparators mentioned are all very fussy about layout and have self-oscillation problems if you\'re not careful about every little thing.
No part is cheap if it takes up space on a crowded board.

Many Greenpak devices have comparators in them, but few have opamps.

I just want to say I am so thankful to have you around to set me straight. Well, my word, what could I do without you.

WTF you think a part like this just might be for?

https://www.ti.com/lit/ds/symlink/lm392-n.pdf
Beware note 5!

LOL- I\'m aware of that one. A powered down circuit with input signals coming from the external world is a similar gotcha.

 

[John Larkin]

On Sat, 19 Nov 2022 12:43:43 -0800 (PST), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:

On Saturday, November 19, 2022 at 12:15:47 PM UTC-5, John Larkin wrote:
On Sat, 19 Nov 2022 03:04:01 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

On Saturday, November 19, 2022 at 2:34:34 AM UTC-5, Ricky wrote:
On Friday, November 18, 2022 at 9:15:53 PM UTC-5, Fred Bloggs wrote:
On Thursday, November 17, 2022 at 3:20:08 PM UTC-5, sonnic...@gmail.com wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a open-collector output.
Does the group know about comparators with driver output, hence can pull up and down, and output like an ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could balance itself
You could use an op amp to buffer the LM393 OC output. Two cheap parts are still cheap. The super fast comparators mentioned are all very fussy about layout and have self-oscillation problems if you\'re not careful about every little thing.
No part is cheap if it takes up space on a crowded board.

Many Greenpak devices have comparators in them, but few have opamps.

I just want to say I am so thankful to have you around to set me straight. Well, my word, what could I do without you.

WTF you think a part like this just might be for?

https://www.ti.com/lit/ds/symlink/lm392-n.pdf
Beware note 5!

LOL- I\'m aware of that one. A powered down circuit with input signals coming from the external world is a similar gotcha.

That whole generation - LM324, LM339 - got crazy if any input went a
little negative. Crazy between sections.

And an LM324 opamp makes a horrible comparator, because internal
current sources are shared among four opamps.

That whole generation is nasty.

 

[Phil Hobbs]

John Larkin wrote:

On Sat, 19 Nov 2022 03:04:01 -0800 (PST), Fred Bloggs
bloggs.fredbloggs.fred@gmail.com> wrote:

On Saturday, November 19, 2022 at 2:34:34 AM UTC-5, Ricky wrote:
On Friday, November 18, 2022 at 9:15:53 PM UTC-5, Fred Bloggs wrote:
On Thursday, November 17, 2022 at 3:20:08 PM UTC-5, sonnic...@gmail.com wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a open-collector output.
Does the group know about comparators with driver output, hence can pull up and down, and output like an ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could balance itself
You could use an op amp to buffer the LM393 OC output. Two cheap parts are still cheap. The super fast comparators mentioned are all very fussy about layout and have self-oscillation problems if you\'re not careful about every little thing.
No part is cheap if it takes up space on a crowded board.

Many Greenpak devices have comparators in them, but few have opamps.

I just want to say I am so thankful to have you around to set me straight. Well, my word, what could I do without you.

WTF you think a part like this just might be for?

https://www.ti.com/lit/ds/symlink/lm392-n.pdf

Beware note 5!

Yup. It\'s a glorified LM358--Which Is Fiiiinnne.

Cheers

Phil Hobbs

(LM358 fan)

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Phil Hobbs]

John Larkin wrote:

On Sat, 19 Nov 2022 12:43:43 -0800 (PST), Fred Bloggs
bloggs.fredbloggs.fred@gmail.com> wrote:

On Saturday, November 19, 2022 at 12:15:47 PM UTC-5, John Larkin wrote:
On Sat, 19 Nov 2022 03:04:01 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

On Saturday, November 19, 2022 at 2:34:34 AM UTC-5, Ricky wrote:
On Friday, November 18, 2022 at 9:15:53 PM UTC-5, Fred Bloggs wrote:
On Thursday, November 17, 2022 at 3:20:08 PM UTC-5, sonnic...@gmail.com wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a open-collector output.
Does the group know about comparators with driver output, hence can pull up and down, and output like an ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could balance itself
You could use an op amp to buffer the LM393 OC output. Two cheap parts are still cheap. The super fast comparators mentioned are all very fussy about layout and have self-oscillation problems if you\'re not careful about every little thing.
No part is cheap if it takes up space on a crowded board.

Many Greenpak devices have comparators in them, but few have opamps.

I just want to say I am so thankful to have you around to set me straight. Well, my word, what could I do without you.

WTF you think a part like this just might be for?

https://www.ti.com/lit/ds/symlink/lm392-n.pdf
Beware note 5!

LOL- I\'m aware of that one. A powered down circuit with input signals coming from the external world is a similar gotcha.

That whole generation - LM324, LM339 - got crazy if any input went a
little negative. Crazy between sections.

And an LM324 opamp makes a horrible comparator, because internal
current sources are shared among four opamps.

That whole generation is nasty.

The original 324 had that problem, but IIRC the 324A has separate bias
generators for each section.

One shining virtue of those parts is that the inputs are lateral PNPs.

\"Wait a minute\", I hear you cry--\"Laterals are super slow and have
crappy beta!\"

Yes, it\'s all true, but their BV_EBO is like 40V, so you can run the
inputs way above the supply voltage with no issues.

Below ground, not so much.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Ricky]

On Saturday, November 19, 2022 at 3:41:59 PM UTC-5, Fred Bloggs wrote:

On Saturday, November 19, 2022 at 12:03:50 PM UTC-5, Ricky wrote:
On Saturday, November 19, 2022 at 6:04:05 AM UTC-5, Fred Bloggs wrote:
On Saturday, November 19, 2022 at 2:34:34 AM UTC-5, Ricky wrote:
On Friday, November 18, 2022 at 9:15:53 PM UTC-5, Fred Bloggs wrote:
On Thursday, November 17, 2022 at 3:20:08 PM UTC-5, sonnic...@gmail.com wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a open-collector output.
Does the group know about comparators with driver output, hence can pull up and down, and output like an ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could balance itself
You could use an op amp to buffer the LM393 OC output. Two cheap parts are still cheap. The super fast comparators mentioned are all very fussy about layout and have self-oscillation problems if you\'re not careful about every little thing.
No part is cheap if it takes up space on a crowded board.

Many Greenpak devices have comparators in them, but few have opamps.
I just want to say I am so thankful to have you around to set me straight. Well, my word, what could I do without you.

WTF you think a part like this just might be for?

https://www.ti.com/lit/ds/symlink/lm392-n.pdf
What are you talking about???

I like that you picked a part that comes in tiny packages, like DIPs. Even the SOIC is a large package these days.

Figure 1. SOIC and PDIP Packages

WTF is going on with you? An opamp and a comparator is always going be a larger package than a simple comparator that does the job.

--

Rick C.

++ Get 1,000 miles of free Supercharging
++ Tesla referral code - https://ts.la/richard11209
https://vendor.ultralibrarian.com/TI/embedded/?gpn=LM392&package=DGK&pin=8&sid=&c=1

https://www.ti.com/lit/ml/mpds028d/mpds028d.pdf?ts=1668889533066&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FLM392

Dimensions mm, multiply by 0.04 ( or 0.039) to convert to inches.

3.00mm longest dimension looks pretty small to me.

Again, I ask WTF is wrong with you? The LM392-N does not come in the DCK package according to the data sheet you linked to. SOIC-8 which is 5x6 mm. It is trivial to find a comparator in a SOT-23-6 package, much smaller.

Do you pay attention to your own posts? I guess that just slipped by, that happens to all of us.

Lots of very delicate precision applications here:

https://www.ti.com/lit/an/snoa667b/snoa667b.pdf?ts=1668889907980&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FLM392

There\'s plenty of stock out there. Seems a bit pricey at $1.50- not sure if that\'s another \"supply chain\" issue or it was always that way. Price is slow to come down in quantity. Makes no difference to a \"one-off\" project.

If it\'s a one off, who cares about much of anything other than getting it to work?

--

Rick C.

--- Get 1,000 miles of free Supercharging
--- Tesla referral code - https://ts.la/richard11209

 

[Fred Bloggs]

On Saturday, November 19, 2022 at 5:16:00 PM UTC-5, Ricky wrote:

On Saturday, November 19, 2022 at 3:41:59 PM UTC-5, Fred Bloggs wrote:
On Saturday, November 19, 2022 at 12:03:50 PM UTC-5, Ricky wrote:
On Saturday, November 19, 2022 at 6:04:05 AM UTC-5, Fred Bloggs wrote:
On Saturday, November 19, 2022 at 2:34:34 AM UTC-5, Ricky wrote:
On Friday, November 18, 2022 at 9:15:53 PM UTC-5, Fred Bloggs wrote:
On Thursday, November 17, 2022 at 3:20:08 PM UTC-5, sonnic...@gmail.com wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a open-collector output.
Does the group know about comparators with driver output, hence can pull up and down, and output like an ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could balance itself
You could use an op amp to buffer the LM393 OC output. Two cheap parts are still cheap. The super fast comparators mentioned are all very fussy about layout and have self-oscillation problems if you\'re not careful about every little thing.
No part is cheap if it takes up space on a crowded board.

Many Greenpak devices have comparators in them, but few have opamps.
I just want to say I am so thankful to have you around to set me straight. Well, my word, what could I do without you.

WTF you think a part like this just might be for?

https://www.ti.com/lit/ds/symlink/lm392-n.pdf
What are you talking about???

I like that you picked a part that comes in tiny packages, like DIPs. Even the SOIC is a large package these days.

Figure 1. SOIC and PDIP Packages

WTF is going on with you? An opamp and a comparator is always going be a larger package than a simple comparator that does the job.

--

Rick C.

++ Get 1,000 miles of free Supercharging
++ Tesla referral code - https://ts.la/richard11209
https://vendor.ultralibrarian.com/TI/embedded/?gpn=LM392&package=DGK&pin=8&sid=&c=1

https://www.ti.com/lit/ml/mpds028d/mpds028d.pdf?ts=1668889533066&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FLM392

Dimensions mm, multiply by 0.04 ( or 0.039) to convert to inches.

3.00mm longest dimension looks pretty small to me.
Again, I ask WTF is wrong with you? The LM392-N does not come in the DCK package according to the data sheet you linked to. SOIC-8 which is 5x6 mm. It is trivial to find a comparator in a SOT-23-6 package, much smaller.

You\'re so inexperienced you think a datasheet tells you all you need to know about a part?

Rick C.

--- Get 1,000 miles of free Supercharging
--- Tesla referral code - https://ts.la/richard11209

 

[Phil Hobbs]

Ricky wrote:

On Friday, November 18, 2022 at 6:00:51 PM UTC-5, Jasen Betts wrote:
On 2022-11-17, sonnic...@gmail.com <sonnic...@gmail.com> wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a
open-collector output. Does the group know about comparators with
driver output, hence can pull up and down, and output like an
ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could
balance itself

WBR Sonnich
John Larkin likes using LVDS receivers as fast comparators. they
will have driver outputs.

If the input signal levels are compatible and you can wear the
typically larger offset votlage you may find that could be a
solution.

The trouble with using a digital differential input as an analog
comparator, is they are not specified for the same sort of
performance. For example, the input offset can typically be rather
large. Maybe in experiments, they prove to work well with low
offsets, but there\'s no good reason to use such a device in an
application it is not specified for... or I should say, unspecified
for.

Also, LVDS receivers seldom have wide common mode ranges.

The ones I use do. FIN1002 is pretty nearly RRI, for one.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Ricky]

On Saturday, November 19, 2022 at 8:06:44 PM UTC-5, Fred Bloggs wrote:

On Saturday, November 19, 2022 at 5:16:00 PM UTC-5, Ricky wrote:
On Saturday, November 19, 2022 at 3:41:59 PM UTC-5, Fred Bloggs wrote:
On Saturday, November 19, 2022 at 12:03:50 PM UTC-5, Ricky wrote:
On Saturday, November 19, 2022 at 6:04:05 AM UTC-5, Fred Bloggs wrote:
On Saturday, November 19, 2022 at 2:34:34 AM UTC-5, Ricky wrote:
On Friday, November 18, 2022 at 9:15:53 PM UTC-5, Fred Bloggs wrote:
On Thursday, November 17, 2022 at 3:20:08 PM UTC-5, sonnic...@gmail.com wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a open-collector output.
Does the group know about comparators with driver output, hence can pull up and down, and output like an ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could balance itself
You could use an op amp to buffer the LM393 OC output. Two cheap parts are still cheap. The super fast comparators mentioned are all very fussy about layout and have self-oscillation problems if you\'re not careful about every little thing.
No part is cheap if it takes up space on a crowded board.

Many Greenpak devices have comparators in them, but few have opamps.
I just want to say I am so thankful to have you around to set me straight. Well, my word, what could I do without you.

WTF you think a part like this just might be for?

https://www.ti.com/lit/ds/symlink/lm392-n.pdf
What are you talking about???

I like that you picked a part that comes in tiny packages, like DIPs. Even the SOIC is a large package these days.

Figure 1. SOIC and PDIP Packages

WTF is going on with you? An opamp and a comparator is always going be a larger package than a simple comparator that does the job.

--

Rick C.

++ Get 1,000 miles of free Supercharging
++ Tesla referral code - https://ts.la/richard11209
https://vendor.ultralibrarian.com/TI/embedded/?gpn=LM392&package=DGK&pin=8&sid=&c=1

https://www.ti.com/lit/ml/mpds028d/mpds028d.pdf?ts=1668889533066&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FLM392

Dimensions mm, multiply by 0.04 ( or 0.039) to convert to inches.

3.00mm longest dimension looks pretty small to me.
Again, I ask WTF is wrong with you? The LM392-N does not come in the DCK package according to the data sheet you linked to. SOIC-8 which is 5x6 mm. It is trivial to find a comparator in a SOT-23-6 package, much smaller.
You\'re so inexperienced you think a datasheet tells you all you need to know about a part?

Clearly I\'m not as wise as you.

https://www.ti.com/product/LM392-N#order-quality

Show me again the DCK package for this part? Onsemi doesn\'t even have the DIP, just the SOIC.

Why are you playing this game???

--

Rick C.

--+ Get 1,000 miles of free Supercharging
--+ Tesla referral code - https://ts.la/richard11209

 

[John Larkin]

On Sat, 19 Nov 2022 21:27:38 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

Ricky wrote:
On Friday, November 18, 2022 at 6:00:51 PM UTC-5, Jasen Betts wrote:
On 2022-11-17, sonnic...@gmail.com <sonnic...@gmail.com> wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a
open-collector output. Does the group know about comparators with
driver output, hence can pull up and down, and output like an
ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could
balance itself

WBR Sonnich
John Larkin likes using LVDS receivers as fast comparators. they
will have driver outputs.

If the input signal levels are compatible and you can wear the
typically larger offset votlage you may find that could be a
solution.

The trouble with using a digital differential input as an analog
comparator, is they are not specified for the same sort of
performance. For example, the input offset can typically be rather
large. Maybe in experiments, they prove to work well with low
offsets, but there\'s no good reason to use such a device in an
application it is not specified for... or I should say, unspecified
for.

Also, LVDS receivers seldom have wide common mode ranges.

The ones I use do. FIN1002 is pretty nearly RRI, for one.

Cheers

Phil Hobbs

Most work from below ground up to almost the + rail.

 

[Phil Hobbs]

John Larkin wrote:

On Sat, 19 Nov 2022 21:27:38 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

Ricky wrote:
On Friday, November 18, 2022 at 6:00:51 PM UTC-5, Jasen Betts wrote:
On 2022-11-17, sonnic...@gmail.com <sonnic...@gmail.com> wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a
open-collector output. Does the group know about comparators with
driver output, hence can pull up and down, and output like an
ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could
balance itself

WBR Sonnich
John Larkin likes using LVDS receivers as fast comparators. they
will have driver outputs.

If the input signal levels are compatible and you can wear the
typically larger offset votlage you may find that could be a
solution.

The trouble with using a digital differential input as an analog
comparator, is they are not specified for the same sort of
performance. For example, the input offset can typically be rather
large. Maybe in experiments, they prove to work well with low
offsets, but there\'s no good reason to use such a device in an
application it is not specified for... or I should say, unspecified
for.

Also, LVDS receivers seldom have wide common mode ranges.

The ones I use do. FIN1002 is pretty nearly RRI, for one.

Cheers

Phil Hobbs

Most work from below ground up to almost the + rail.

Yup. The FIN1002 datasheet has a delay vs. CM voltage plot that\'s
pretty well dead flat from -0.4V to +2.8, running off a 3.3V rail.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[John Larkin]

On Sun, 20 Nov 2022 13:29:24 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

John Larkin wrote:
On Sat, 19 Nov 2022 21:27:38 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

Ricky wrote:
On Friday, November 18, 2022 at 6:00:51 PM UTC-5, Jasen Betts wrote:
On 2022-11-17, sonnic...@gmail.com <sonnic...@gmail.com> wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a
open-collector output. Does the group know about comparators with
driver output, hence can pull up and down, and output like an
ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could
balance itself

WBR Sonnich
John Larkin likes using LVDS receivers as fast comparators. they
will have driver outputs.

If the input signal levels are compatible and you can wear the
typically larger offset votlage you may find that could be a
solution.

The trouble with using a digital differential input as an analog
comparator, is they are not specified for the same sort of
performance. For example, the input offset can typically be rather
large. Maybe in experiments, they prove to work well with low
offsets, but there\'s no good reason to use such a device in an
application it is not specified for... or I should say, unspecified
for.

Also, LVDS receivers seldom have wide common mode ranges.

The ones I use do. FIN1002 is pretty nearly RRI, for one.

Cheers

Phil Hobbs

Most work from below ground up to almost the + rail.

Yup. The FIN1002 datasheet has a delay vs. CM voltage plot that\'s
pretty well dead flat from -0.4V to +2.8, running off a 3.3V rail.

Cheers

Phil Hobbs

It\'s convenient to have a grounded LC tank that drives a grounded LVDS
receiver with a zero threshold.

A general-purpose 10 MHz clock input, for example. A user might apply
most any waveform and amplitude. Series DC block cap+Resistor+LC+LVDS
cleans up nearly anything.

 

[Phil Hobbs]

John Larkin wrote:

On Sun, 20 Nov 2022 13:29:24 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

John Larkin wrote:
On Sat, 19 Nov 2022 21:27:38 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

Ricky wrote:
On Friday, November 18, 2022 at 6:00:51 PM UTC-5, Jasen Betts wrote:
On 2022-11-17, sonnic...@gmail.com <sonnic...@gmail.com> wrote:
Hi all

A standard comparator f.x LM393, LM2903 etc commonly have a
open-collector output. Does the group know about comparators with
driver output, hence can pull up and down, and output like an
ordinary opamp?

How do I search for such ones?

An ordinary opamp does not fit my need, as my application could
balance itself

WBR Sonnich
John Larkin likes using LVDS receivers as fast comparators. they
will have driver outputs.

If the input signal levels are compatible and you can wear the
typically larger offset votlage you may find that could be a
solution.

The trouble with using a digital differential input as an analog
comparator, is they are not specified for the same sort of
performance. For example, the input offset can typically be rather
large. Maybe in experiments, they prove to work well with low
offsets, but there\'s no good reason to use such a device in an
application it is not specified for... or I should say, unspecified
for.

Also, LVDS receivers seldom have wide common mode ranges.

The ones I use do. FIN1002 is pretty nearly RRI, for one.

Cheers

Phil Hobbs

Most work from below ground up to almost the + rail.

Yup. The FIN1002 datasheet has a delay vs. CM voltage plot that\'s
pretty well dead flat from -0.4V to +2.8, running off a 3.3V rail.

Cheers

Phil Hobbs

It\'s convenient to have a grounded LC tank that drives a grounded LVDS
receiver with a zero threshold.

A general-purpose 10 MHz clock input, for example. A user might apply
most any waveform and amplitude. Series DC block cap+Resistor+LC+LVDS
cleans up nearly anything.

Good idea. Some instruments insist on TTL levels, which is a bit of a
nuisance.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com