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Old 30th April 2007, 09:07 PM   #1
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Default Prototype and risk

From some suppliers as TI, it's possible to order prototype sample.

What is the risk to use these components for a long period of time?

To have a example, TI have the OPA827.

http://focus.ti.com/docs/prod/folders/print/opa827.html

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Old 1st May 2007, 12:53 AM   #2
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They do not send out parts that are not "production" parts. They will work fine as long as any of the same part number.

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Old 1st May 2007, 02:40 AM   #3
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Yes ... confidence is high that what you get will work as advertised ... they (and most main line chip makers) don't make that kind of mistake any more. = Good stuff, use it with confidence. The only down side is if they don't get much response from DIY types / engineers / customers, then they might not produce a full production run ...
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Old 1st May 2007, 06:19 AM   #4
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Good to know.

I ordered a couple of OPA827 weeks ago and the listening test I've done at DAC output buffer was very pleasant. The sonic signature is close to the OPA627 but with more dynamic (a little) and bass better controlled. No problem with HF. Mediums still have the original BB sonic signature.

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Old 1st May 2007, 03:49 PM   #5
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http://focus.ti.com/lit/ds/symlink/opa827.pdf = the diagram on page one ... note the dual capacitors at the power pins = TI and others will use polystyrene caps (or other plastic types) as a "snubbing" cap = the 100 nF cap, and regular electrolytics for the 2.2 uF cap here. The idea is that the electros are a little slower responding to higher freq. noise on the power lines and the snubbing caps are better for this purpose ... in parallel and "close coupled" to the chips power pins = reported specs are the best (optimized) = Common Mode Rejection is better and distortion is lower, etc.

Generally the +/- 15 VDC is chosen as resulting specs are a little better at these voltages than lower voltages.

(I have 4 coming myself ... but I would rather have had the older style 8-pin mini-DIP package. My usage will be as input buffer for "XLR balanced to unbalanced" front end for a power amp ala: http://www.diyaudio.com/forums/showt...01#post1187301 )
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Old 1st May 2007, 04:03 PM   #6
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Quote:
Originally posted by FastEddy
[B]http://focus.ti.com/lit/ds/symlink/opa827.pdf = the diagram on page one ... note the dual capacitors at the power pins = TI and others will use polystyrene caps (or other plastic types) as a "snubbing" cap = the 100 nF cap, and regular electrolytics for the 2.2 uF cap here.
I already have this in the circuit (very close to the pins). But the 100nF is ceramic and the 2.2uF is a Tantalum 20uF. The circuit was build for an OPA2134 and the OPA827 fit plug-an-play (and 627 too).

I also tried this inside another circuit (100nF MKP + 47uF chimical) with an LM4562 and the result was very good (less HF).

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