Awesomely complex IC

[Demon-Xanth]

http://pdfserv.maxim-ic.com/en/ds/MAX5491.pdf

We've come up to a few possible reasons for this part:
#1: The engineer couldn't be fired due to labor laws.
#2: The engineer was retiring in 6 months and they had to keep them busy.
#3: They had a bunch of bad ICs and were trying to find a way to use them.
#4: They're messing with the heads of people at Koa/Speer and Dale/Vishay.


PRESS RELEASE!

 

[TuxDave]

Ok. What's so weird about it? If you need to get a very well matched resistive divider for whatever PCB board you're building, you can now just grab this IC.

 

[Demon-Xanth]

...or two resistors with that tolerance.

There's no point to using an IC (the engineers+techs around here are laughing at this)

 

[blahblah99]

Yeah, what's wrong with this IC? There are 0.1% resistors available, but between multiple 0.1% resistors, you have 0.2% maximum deviation.

 

[JetBlack69]

😕 what's so weird about it?

 

[brxndxn]

Please explain.. I fail to see absurdity in said IC.

 

[Demon-Xanth]

Or 0.01% resistors: http://vishay.com/docs/53017/p.pdf that are even tighter.

And the difference actually doesn't add up that way. If one is 0.1% high, and the other is 0.1% low, the net result is a ladder that's off by 0.1%.

 

[Demon-Xanth]

Absurdity: Making an IC that takes the place of two easily selectable resistors.

 

[TuxDave]

Originally posted by: Demon-Xanth
...or two resistors with that tolerance.

There's no point to using an IC (the engineers+techs around here are laughing at this)

Umm... it's 67 cents, it gives you a resistive divider that within 0.035% accuracy over a large temperature range. Sometimes you just need something like this.

 

[blahblah99]

Originally posted by: Demon-Xanth
Or 0.01% resistors: http://vishay.com/docs/53017/p.pdf that are even tighter.

And the difference actually doesn't add up that way. If one is 0.1% high, and the other is 0.1% low, the net result is a ladder that's off by 0.1%.

Not really.. it all depends on the application. If you have a string of 0.1% resistors the error can be larger than 0.1%. Take for, example, a string of 4 resistors in which the first 3 are 0.99R and the last one is 1.01R. With 1% resistors, the expected voltage would be 0.25Vin but you get 0.253769Vin.

That's more than 1.5% error.


Anyhow, just cause you see no value in an IC doesn't mean it's useless. If it was utterly useless, then they wouldn't have released such a product. I can list tons of applications that require this component.