[sdiy] low supply voltage dual opamp ??? solved..

Tim Ressel timr at circuitabbey.com
Wed Sep 21 20:44:54 CEST 2016


Sometimes you can do a search online and find a marking number. I've 
done this with SMT components that have codes rather than part numbers.

It gets frustrating. The stuff gets so small they don't mark them at 
all. If you drop an SMT cap you have to write it off because they are 
not marked at all. And when SMT chips are marked they use laser etching 
(I guess) that is very hard to read. Long gone are the days of 1 watt 
resistors with big clear color bands. Now you get little 1/8 watters and 
the colors are milky and you cannot tell if its red or orange.

Then you get big company A buying out big company B and magically all 
the really cool info in the datasheets get cut out, for reasons I cannot 
fathom. I used to have a massive library of data books. Then the 
internet came along and I got rid of most of them because I could just 
look it up. But now a lot of that stuff is gone. I still have a Linear 
Applications Handbook for that very reason.

--tr

On 9/21/2016 11:12 AM, Christian Tecl wrote:
> Hi folks,
>
> that's a well known problem, these smd codes aren't as realiable as 
> they should be (or could be...) The reasons why are countless... Main 
> reasons are the manufac-date, copy right / patent issues and the 
> manufacturer themselves...
>
> The electronic component market is changing so fast, so few of the 
> former big players are manufacturing till today. And surprise 
> surprise, they are the ones where the codes are leading you to the 
> right components or their replacements...
> The company I work for is mainly doing service support for industrial 
> elect. devices. Nearly all of the employees are highly experienced and 
> educated pros, but the time that they and we all spend, or say loose 
> by searching for components, codes, replacings.... It's just horroble...
> The only option you have is to look into old katalogs (if you know the 
> manufacturer or/and prod.
> date/timespan) or you go asking the right persons......
> Very preferable would be an overall database with a useful amount of 
> the old katalogs, an intelligent meta-search function - connected to 
> the common databases and some other goodies - like a help forum with a 
> reliable help valuation system...lot more ideas hanging round here.
> It's been a while, since I play around with that idea, to do on my 
> own, but time is very limited 'till summer 2018... And then... We'll 
> see, you never know... "LIFE"
>
> I know there are sites that deliver some of the things mentioned, 
> but... You all know...! It's fucked up!
>
> So, sorry for the Off-Topic.
>
> "This was straight down, while I searched that 690 / 055 ic you were 
> asking..."
>
> Greetings
>
> Christian T.
> -- 
> Diese Nachricht wurde von meinem Android Mobiltelefon mit GMX Mail 
> gesendet.
> Am 2016.09.21, 15:01, Jean-Pierre Desrochers <jpdesroc at oricom.ca> 
> schrieb:
>
>     Thanks to you all.. specially Paul..
>
>     The Microchip MCP6002 will effectively do the job here..
>
>     (But I still don't understand the "690 055" lettering on the
>     original 8SOIC chip... )
>
>     JP
>
>     ***************************************
>
>     Le 2016-09-21 07:39, Jean-Pierre Desrochers a écrit :
>
>         I'm back guys with my request..
>         Paul suggested it was an OPA690.
>         Well it looks it's not.
>         The OPA690 is a single opamp.
>         The one I need to replace is a dual opamp
>         (same pinout as the TL072.. not TL071).
>         Both outputs are on pins 1 and 7.
>         Supply pins are 4 and 8.
>         So I'm back where I was from start.
>         I need a dual opamp that:
>         - runs on 5vdc
>         - low power (powered with AAA battery 1.5v stepped up to 5vdc for all
>         circuit)
>         - 8SOIC package
>
>         Any idea the ship that would do ??
>
>         ****************************************************************************
>         *
>
>         -----Message d'origine-----
>         De : Paul Schreiber [mailto:synth1 at airmail.net <mailto:synth1 at airmail.net>]
>         Envoyé : 20 septembre 2016 17:58
>         À : 'Jean-Pierre Desrochers';Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
>         Objet : RE: [sdiy] low supply voltage dual opamp ???
>
>         OPA690. The 055 is the date code
>
>         Paul S.
>
>
>         -----Original Message-----
>         From: Synth-diy [mailto:synth-diy-bounces at dropmix.xs4all.nl
>         <mailto:synth-diy-bounces at dropmix.xs4all.nl>] On Behalf Of
>         Jean-Pierre Desrochers
>         Sent: Tuesday, September 20, 2016 4:55 PM
>         To:Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
>         Subject: [sdiy] low supply voltage dual opamp ???
>
>         I need a low voltage dual opamp for a wireless microphone That runs with one
>         AAA battery. There is a step-up supply voltage circuit that rise the 1.5v to
>         5vdc to supply all the remote circuit including a dual opamp (single supply
>         used). This opamp needs to be changed.
>         All I can say about this opamp is that the case is a 8SOIC and the pinout is
>         the same as a TL072. The lettering on the case is :
>         690 followed by 055 (or D55 ???).
>         So I'm looking for a low supply voltage, low power and quiet dual opamp to
>         replace it.
>         Any idea ?
>         Thamks.
>         JP
>
>
>
>         _______________________________________________
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>     -- 
>
>              « L'indépendance, c'est comme un pont :
>     avant, personne n'en veut, après, tout le monde le prend. »
>     Félix Leclerc
>
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-- 
--Tim Ressel
Circuit Abbey
timr at circuitabbey.com

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