Electronics > Projects, Designs, and Technical Stuff
Chip doesn't show up in manufacturer's parametric search?
maxwell3e10:
I was looking for some op-amps on TI website and found that OPA627 doesn't show in any parametric search. Yet its listed as an active chip if searched for directly.
I am wondering if its just a glitch specific to this particular chip or something chip makers do routinely to phase out older designs? Is it actually better to do parametric search on something like Digikey instead of manufacturer's site?
Kleinstein:
I also noticed that the search sometimes did not show some chips - in my case audio grade OPs like OPA1642 and similar.
There are quite a few extra parameters and some may exclude some chips. Anyway the search seems to change from time to time so it may be already be different now. With older parts it may happen they enter wrong data in the lists. I don't think they intentionally skip the older parts - they may be just miss some properties in the database (e.g. package family, type (BJT,JFET,CMOS), price). Ideally they would put the old parts to the bottom of the list.
The search at the distributors is also not always that convenient. The main problem there is the way the supply voltage range is handled - a long list with lots of ranges (e.g. 3 - 12 , 3.3 - 6 , ... is not practical at all). In addition there seem to be quite some errors in those lists - it mainly gets obvious when you get parts shown that do not fit at all, but one would likely also miss some due to wrong entries. The big advantage at the distributors is that one gets parts from different sources including some of the less common ones (e.g. ST, Toshiba, Samsung).
Ian.M:
GIGO has been a problem in large collections of data for over 150 years* and component manufacturers and distributors parametric databases are far from immune. e.g. Microchip's database underlying their MAPS parametric search and their various product range selectors is well known to be heavily contaminated with bad data - this is obvious as large portions of it can be accessed as CSV spreadsheets from the product range pages and in many cases a part isn't even entered in the correct product range.
Voltage ranges are -in theory- quite easy to handle in web based parametric searches. A single or multiple item selection can never be satisfactory. Instead the max. and min. voltages must be stored in the database and the user allowed to set upper and lower limits for each as search criteria. However the managers who sign off on the parametric search U.I. development typically have never used a soldering iron, so engineers continue to get almost unusable parametric search engines foisted on us by MBAs.
* Charles Babbage in his 1864 book "Passages from the Life of a Philosopher"
--- Quote ---On two occasions I have been asked, — "Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?" In one case a member of the Upper, and in the other a member of the Lower, House put this question. I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question.
--- End quote ---
Zeyneb:
I've a positive experience with the Digikey website to find parts I'm interested in. Sure, not all data is correct, but it's obvious to me Digikey really strives for perfection regarding this. If you find something incorrect and when you can back this up with information from the manufacturer they are very eager to correct it soon. Just leave them a short message. Maybe you will help a fellow Eevblog forum member also by doing so.
maxwell3e10:
Yes, Digikey seems to have the best for parametric search compared with other distributors. The voltage range is annoying. it seems the best solution is to select all other parameters first and then pick a few choices for the voltage range.
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