Free 30 piece amplifier kit from Analog Devices
May 14, 2002 at 3:05 AM Thread Starter Post #1 of 18

zCereal

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http://www.analog.com/technology/amp...promotion.html

i got this kit in the mail today
comes with 30 little various amplifier integrated circuits
(each kit contains same components)

they got some fairly nice stuff in here that you mgiht wanna check out and the free factor is good

lemme know what you manage to build with these as i want to build something of my own but don't have the technical know how

(these are very tiny chips too about 3mm by 3mm)

so order yours
it'll be there in about 5 business days (only available in US and canada)
 
May 14, 2002 at 7:08 AM Post #2 of 18

vn412

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thanks! i ordered one just now!

I would also be interested in what ppl come up with
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May 14, 2002 at 7:16 AM Post #3 of 18

tangent

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I just got mine today, too.

The only chips I recognize are the AD8610 (only one, though), the AD8512 (yay!), and the OP27 (always wanted to try that old design to see how it compares to modern stuff).

Everything else is a mystery to me.

All the chips in my kit except one are SO-8, so they will require air-wiring, or one of the two Brown Dog adapters to convert them to DIP-8. The last chip is even tinier. MSOP or something nearly invisible like that.
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May 14, 2002 at 8:30 AM Post #4 of 18

tangent

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This chip assortment is definitely a mixed bag. Alongside stellar performers like the AD8610 and the AD8512 you have real dogs like the OP281. Let me tell you about the 281:

Slew rate: 25 V/ms Decent audio opamps measure this in V/us, and 25 V/us -- same signal level in 1000th the time! -- is pretty easy to hit these days.

Gain/bandwidth product: 95 kHz. Chips with a GBP of 4 MHz are considered dogs for audio use. Chips with GBP in excess of 95 MHz aren't unheard of for audio.

Noise: 70 nV/rt.Hz That means that at 20 kHz, you'll get about -80 dB of noise relative to a 1V signal, which isn't bad, really. (It gets better as the frequency goes down.) Still, common opamps used for audio are down in the single-digit nV/rt.Hz range.

I'm deliberately picking on the worst chip in the batch. There's some good stuff in here. But, I do wish they'd put something more interesting in like the AD825 instead of these jellybean parts.

Also, beware that the chips aren't all op-amps. 8 or so of them are instrumentation or differential amps.

Some random thoughts on the other chips in the kit:

OP184: on first glance, it looks a lot like the Burr-Brown OPA131, the older generation of the well-regarded OPA132. Could be usable in an amp...

AD8628: rather under-specified for audio (it's worse than the OPA131) but extremely low noise specs. Could be interesting to try in an amp, just to see.... Also the AD820, which is specified like it's an early version of the AD823.

AD8606: Similar to an OPA132, but better in most respects. Not quite as good as an AD823, but quite respectable. Also, it claims 80 mA output current. Not bad at all!

AD8007: A current-feedback amplifier with 600 MHz GBP. That's not a typo. 600 MHz! Keeping this dude stable sounds like it would be a minor nightmare... This chip was released just this month, so the datasheet on the included mini-CD doesn't have many details about the chip. There are a few other similar chips in the kit, too, such as the AD8014, a 400 MHz CFB chip. Yikes!

But you don't have to go with a CFB to get triple digit bandwidth. There's the AD8021 at 490 MHz at G=1. At G=10, it's a "mere" 150 MHz. Zoom zoom.
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The microscopic chip is the AD8072, by process of elimination. The chip is so small that they could only fit three letters on it.
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It's not MSOP -- they call the package uSOIC. Hmmmm...
 
May 14, 2002 at 4:21 PM Post #5 of 18

Duncan

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This appears to be more suitable in the DIY section, so i'm placing it there
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Thanks
 
May 14, 2002 at 11:40 PM Post #7 of 18

eric343

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I believe that uSOIC == SSOP, because the DIP <-> SSOP adapter on my rev i2 META board was actually for an AD uSOIC chip, and the chip fit!
 
May 17, 2002 at 8:10 AM Post #10 of 18

Joobu

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Um. Mind you, the OP281 uses 4uA/channel. The ad8610 uses 3,000 uA/channel.

It's all about a different set of priorities. So let's say you're stuck in space with several AA batteries, the OP281 would last about oh... say 1000 times longer.

Noise at a specific frequency is meaningless. The calculation is based on the noise in a given frequency range. So, for the audio range of 20Hz-20kHz, the noise is 70nV*sqrt(19.98k)=9.9uV which is -100dB.
 
Jul 2, 2002 at 10:21 PM Post #11 of 18

geom_tol

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I've looked at these op-amps etc. now and I don't need them. If anyone wants my kit send me a mail and I'll send the kit to you.
(I'm keeping the ad8512 though).
This will be useful for meta42 builders that have the kit already cause you'll have two of the ad8610 after you get my kit.

The little cd with app notes is cool, if you haven't checked it out do it, it's a great collection of app notes since many of them apply to the stuff we're doing.

Cheers!
 
Jul 3, 2002 at 2:10 AM Post #14 of 18

geom_tol

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andrzejpw: Cool! I will do it also.
On paper it seems pretty good. I like the fact it will take +/-15V supply voltage. Which is more 'standard' for ac powersupplies.

Tangent: Did you get a chance to try this ic?
 

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