Does this comparator exist....

How about a TL431? ;)

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

Cheers

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

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

Can you do anything with this window comparator?

Cheers

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

Vin1 > Vin2 + delta

Both Vin1 and Vin2 can move ...Jim Thompson

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

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

Sno-o-o-o-ort, ROTFLMAO >:-} ...Jim Thompson

Good idea. I'll check 'em out. Thanks! ...Jim Thompson

Yeah, but he considers a 555 a boutique part.

max9000 plus four resistors to make a subtractor ?

-Lasse

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.

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)

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.

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 . | / --------------- . . . . .

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

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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