723 vs L146 a copy/clone, spinoff or an improved version?

Discussion in 'General Electronics Chat' started by ChrisChemist116, Mar 18, 2010.

  1. ChrisChemist116

    Thread Starter Active Member

    Mar 13, 2009
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    I believe everyone in the forum knows very well that for many years 723 was used to make many kinds of power supply circuits for beginners, electronic enthusiasts and as well students. :)

    So with that in mind, while i was trying to find a circuit i could start with

    i found this schematic where it mentions the L146. http://www.elecfree.com/electronic/...146lm327-power-supply-regulator-0-40v-08a.jpg (i believe after looking at the style, the schematic comes from a scanned copy from an old elektor magazine)

    I am not like the NTE reference guide (if you know what i mean) and because that chip seemed to be some strange for me i decided to look into datasheets and i found it under this link: http://www.datasheet4u.com/download.php?id=501427
    http://www.datasheet4u.com/html/L/1/4/L146CB_ETC.pdf.html

    As well i compared with other manufacturers of the 723 (including national semiconductor, ST Microelectronics, Texas instruments. And i found really very few differences between the L146 and 723.

    However datasheets dont explain very well which performs best?, as far as i see it, it seems L146 offers higher input voltage 80V over 40V offered by LT.

    I can't identify L146 manufacturer. Could anyone give me a clue on that?:confused:

    And more importantly, what's the big deal with L146 and 723? . Is it an improved version, a cheap clone?, a copy,? a spinoff?.:confused:
     
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    I never new abt L146, It see that is better suitable for my needs.
    I wonder why no body suggested that chip for my supply.
     
  3. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    It is same as 723.
    Same diagram as LM723 with only the chip label changed.
    Is it a rip off.
    It does offer high voltage though
     
    ChrisChemist116 likes this.
  4. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    N it costs USD 24.00 a piece :mad:
     
  5. t06afre

    AAC Fanatic!

    May 11, 2009
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    I guess it is out of production, and the marked has been left to the "parasitic" hard to get components firms
     
  6. ChrisChemist116

    Thread Starter Active Member

    Mar 13, 2009
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    I can see both have the same pinouts and exhibit the same diagram, but how do L146 offers higher voltage input and 723 lower one? I think it should be any significant difference in both internal schematics for explain that difference.

    How come? Where do you find it?. Via Digikey perhaps?

    Actually i dont know if there is any way to confirm whether or not if such IC is out of production. But if it is i would like to know.

    As well in my local electronics store they didn't know about the L146 neither.

    Where i can find more information about that chip?:confused:

    Thanks anyways
     
  7. R!f@@

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    I found the chip on ebay from a seller called little usa I think
     
  8. SgtWookie

    Expert

    Jul 17, 2007
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    I think you meant littlediode USA. They are very, very proud of their products. If they were the only vendor I could find for a part I needed, I would look a lot harder or do without it.
     
  9. R!f@@

    AAC Fanatic!

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    Yup ..littlediode USA. it seems u don't like 'em. Sgt.
    I think I did made a purchase from them. But they are expensive.
     
  10. ChrisChemist116

    Thread Starter Active Member

    Mar 13, 2009
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    Is there any way to tell (theoretically speaking) how do one IC has superior voltage input over the other one?
     
  11. SgtWookie

    Expert

    Jul 17, 2007
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    Look at the manufacturer's datasheet.

    If the parts do not live up to the manufacturer's published specifications, they will not be in business for very long.

    I tried searching for an L146 a few days ago, but could not find a datasheet from any specific manufacturer. You might as well seek the Holy Grail. :rolleyes:

    If it seems too good to be true, it generally is.

    Re: littlediode USA - they price their items ridiculously high. As far as I know, they are not an authorized supplier for any manufacturer. This means that you might wind up paying through the nose for counterfeit parts, that will not perform up to the original manufacturer's specifications.

    One should use authorized distributors whenever possible. Mouser, Avnet, Allied Electronics, Digikey, Newark are but a few suppliers who are authorized distributors for many manufacturers, and take care to protect their good standing. When you purchase from reputable authorized distributors, or directly from the manufacturer, you can be pretty certain that the components you receive will perform in accordance with the published specifications.

    If you buy from somewhere else, you may very well pay far too much, and be disappointed in the performance of the parts.

    NTE parts are to be avoided. They are re-branded manufacturers' parts, that carry a premium price. They have a cross-reference search, but it only goes one way; from other manufacturer's part numbers to NTE part numbers. The NTE part will be far more expensive than the original part.

    If you don't believe me on this, prove it to yourself.

    Look up the price for an LM3914 on any authorized distributor for National Semiconductor parts, like Digikey, Allied, Newark.

    Then go to the http://www.nteinc.com website, and find their part number for an LM3914 using the cross-reference tool.
    (hint: NTE1508)

    Then find the price for their equivalent replacement part.
     
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