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Does this comparator exist....

Does this comparator exist....

Has the usual two inputs, inverting and non-inverting, BUT it switches when the DIFFERENCE between the two inputs is some reference value, either fixed/built-in, or adjustable by an extra pin?

I know I could construct such a thing, but I'm looking for something small, minimum pins, etc., i.e. a Joerg part ;-) ...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 | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

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| 1962 | I love to cook with wine. Sometimes I even put it in the food.

Reply to
Jim Thompson
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How about a TL431? ;)

If you want something faster, there's the MCP65R41T.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 USA 
+1 845 480 2058 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

Nope. I would have to add stuff to make that work.

I need a comparator, with a couple of volts of common-mode range, ideally with an adjustable difference between + and - inputs at the switching point, but I can live with something fixed at between 300mV and 500mV.

Seriously! A Joerg part ;-) ...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  |             | 
| Voice:(480)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.
Reply to
Jim Thompson

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

Can you do anything with this window comparator?

Cheers

Reply to
Martin Riddle

Right concept, but I need differential inputs, basically switch when...

Vin1 > Vin2 + delta

Both Vin1 and Vin2 can move ...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  |             | 
| Voice:(480)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.
Reply to
Jim Thompson

Not a Joerg part, because if it did find one he'd complain about it being "boutique".

--
Tim Wescott 
Control system and signal processing consulting 
www.wescottdesign.com
Reply to
Tim Wescott

RS485 receivers might do the trick... but no variable delta.... delta is around 500mV.... ? Maxim do a range...

Reply to
TTman

Sno-o-o-o-ort, ROTFLMAO >:-} ...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  |             | 
| Voice:(480)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.
Reply to
Jim Thompson

Good idea. I'll check 'em out. Thanks! ...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  |             | 
| Voice:(480)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.
Reply to
Jim Thompson

Yeah, but he considers a 555 a boutique part.

Reply to
Michael A. Terrell

max9000 plus four resistors to make a subtractor ?

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-Lasse

Reply to
langwadt

Lots of LVDS-to-CMOS receivers have some built-in offset, ca 100 mV. All the ones that we've tested behave like good r-r comparators. Cheap and fast.

--

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
Reply to
John Larkin

If you trust Maxim to maintain supplies.

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

Reply to
Fred Abse

If you need the inputs high-impedance, this means an instrument amplifier (i.e. two op amps, or three) followed by a comparator (a third op amp, or a real comparator).

And if the inputs can be less 'ideal', you can use an emitter resistor and a transistor to convert delta-V to I, then a resistor on the collector to convert I to V, and a comparator.

Finally, if you look at current-sense gizmos (Zetex ZXCT1009), the accuracy/thermal drift can be made better than that transistor V-to-I, but it's still a three terminal device like a transistor. Don't know how inexpensive it is, though.

Reply to
whit3rd

That's just an ordinary comparator with some creative feedback depending on how much range you need: Please view in a fixed-width font such as Courier.

. . V+ . RF3 >> R | . [RF1} . | . .----[RF3]---+ V1 > V2 + VB1 . | | | - - - . | | \ | | | . V1 >--------+--[R/2]--+--|+ \ [RF2] | . | | \ | | | . [R] | > ---+----> | . | | / | | . V2 >---[R]--+------------|- / | - - - V1< V2 +VB2 . | / --------------- . . . . .

Reply to
bloggs.fredbloggs.fred

I don't know of a part like that. The simplest solution I can think of is a diode and resistor added to the front end of an ordinary comparator(assuming your signals are not hi-Z). Art

Reply to
Fred

message

Damn. I wasn't paying attention and replied from a different account and "Fred" probably isn't going to make it thru your filters. This should. Art

Reply to
Artemus

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