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Help with BS2 parts...Dual NPN & Single PNP — Parallax Forums

Help with BS2 parts...Dual NPN & Single PNP

hmlittle59hmlittle59 Posts: 404
edited 2008-10-02 05:02 in General Discussion
Hello to all,

I'm looking to buy these parts from Mouser, Jameco, or Digikey but they don't have them in stock. Can anyone please advise. I called Tech. Support and got some part numbers but no one seems to have them in stock or know of them. Best they could do is get me a Quote.


Thanks again for any help

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I HAVE LEARN SO MUCH...BUT STILL KNOW SO LITTLE!!!

hmlittle59

Comments

  • hmlittle59hmlittle59 Posts: 404
    edited 2008-09-24 23:16
    OOPP's!!!

    Hello Again,

    I meant to hit View instead of submit.....

    The 2 parts from the BS2 are:

    1) Dual NPN Tans. Pack (10k res. 2n3904)
    2) Single PNP Tans. Pack (10k res. 2n3906)

    where to buy???

    thanks again

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    I HAVE LEARN SO MUCH...BUT STILL KNOW SO LITTLE!!!

    hmlittle59
  • Bruce BatesBruce Bates Posts: 3,045
    edited 2008-09-24 23:25
    hmlittle -

    The FindChips search engine is what I use: http://www.findchips.com/

    Regards,

    Bruce Bates

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    When all else fails, try inserting a new battery.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2008-09-25 02:25
    Is this to replace parts on the BS2 module? If not, do you need these parts in the same tiny SMD package? Then, if not, what package size is required? It would help if you explained your objectives. I'm sure DigiKey has something that will work for you.

    -Phil

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    'Still some PropSTICK Kit bare PCBs left!
  • hmlittle59hmlittle59 Posts: 404
    edited 2008-09-25 03:15
    Digikey said they did not.

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    I HAVE LEARN SO MUCH...BUT STILL KNOW SO LITTLE!!!

    hmlittle59
  • hmlittle59hmlittle59 Posts: 404
    edited 2008-09-25 03:19
    Thanks for the help Bruce, I'll try them.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    I HAVE LEARN SO MUCH...BUT STILL KNOW SO LITTLE!!!

    hmlittle59
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2008-09-25 05:24
    DigiKey may not have the exact parts that Parallax uses, but they may well have adequate replacements. Hence my questions. If you answer them, I may be able to help.

    -Phil

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    'Still some PropSTICK Kit bare PCBs left!
  • Tracy AllenTracy Allen Posts: 6,666
    edited 2008-09-25 15:49
    Here are the Panasonic composite transistors that I have used in the same circuit that is on the Stamps.
    XN1211 dual digital NPN, 10k-10k in SOT23
    UN2111 single digital PNP, 10k-10k in SOT23
    available from Digikey. There are several companies that make these, also called transistor arrays or digital transistors. Digikey also carries the Rohm brand.

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    Tracy Allen
    www.emesystems.com
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2008-09-25 15:49
    hmlittle59 said...(trimmed)
    OOPP's!!!
    Hello Again,
    I meant to hit View instead of submit.....
    You can always edit your message using the pencil icon to the top-right of the message.· Take care.

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    Chris Savage
    Parallax Engineering
  • hmlittle59hmlittle59 Posts: 404
    edited 2008-09-26 03:35
    The Tech. that helped me at (Digikey) only knew of the Dual and Single transistors ...without.. the 10k's.

    Thanks for the Parts help Tracy and I will try the pencil icon next time, thanks


    Thanks for all the help

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    I HAVE LEARN SO MUCH...BUT STILL KNOW SO LITTLE!!!

    hmlittle59
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2008-09-26 08:20
    I suspect the problem is that these are not carried in a retail inventory. It is likely that you have to order thousands of these directly from the chip maker and wait for a production run. We hobbyist can get a lot of PDF files for chips that cannot be gotten in small quantities. Just because it is in the catalog doesn't promise that it is in retail inventory.

    If you are attempting a DIY repair of a BasicStamp, you might try Parallax's customer service. BTW, they do repair BasicStamps if the damage is not too severe.

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  • Tracy AllenTracy Allen Posts: 6,666
    edited 2008-09-26 15:07
    Kramer, Not really for these parts. They are very common and for example Digikey will sell you quantity one XN1211 at 42 cents or a reel of 3000 at 11 cents ea.

    hmlittle59, I don't know why the tech at Digikey gave misleading info, but sometimes you have to have the exact terminology down. If you ask for a dual 2N3904 with 10k resistors they might get thrown off, but with "digital transistor" typed in the Digikey search box, the vista opens up. There lots of different configurations of digital transistor available with different built-in resistors. The characteristics of the transistors themselves are indeed similar to the general purpose 2N3904 or 2N3906.

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    Tracy Allen
    www.emesystems.com
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2008-09-26 17:11
    If the DigiKey tech was given part numbers for Parallax's transistors, the misunderstanding might have been whether the desired characteristics were available in the same package size that Parallax uses (SOT416 for the single), which is much smaller than an SOT23. When I was working on the MoBoStamp, I had the same problem, since DigiKey didn't carry everything I needed in the smaller package.

    -Phil
  • Tracy AllenTracy Allen Posts: 6,666
    edited 2008-09-26 19:53
    Good point Phil. Digikey does stock the single PNP in the 1.6mm SOT416 (e.g. part# DTA114EE) and the dual NPN in the 2mm SOT353 (part# UMA9N). But I can't say that those are the sizes for the Stamp. When I designed the Stache and the OWL2pe, I used the larger (relatively speaking) SOT23.

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    Tracy Allen
    www.emesystems.com
  • hmlittle59hmlittle59 Posts: 404
    edited 2008-09-26 22:46
    Howard again,

    I've done 3 spines on my board with through hole components and a "BS2" in a socket(works great). Now I wanted to move up to SMT components and have purchased all but a few components for my first spine. I first laid out the board with ExpressPCB but thought that I needed to switch software packages. Someone from this forum suggested DipTrace and I love it. Now I'm doing the board with DipTrace software and need to relearn all the SMT symbols to make sure I'm ordering the correct parts. I've found (WWW.intersil.com/design/package) and printed it out. Any way, thanks for all the help and insight. I'll be ordering the parts suggested now.


    thanks again...it's late and I need to get to ordering and parts match up(sizes) in my design.

    thanks again for all the help

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    I HAVE LEARN SO MUCH...BUT STILL KNOW SO LITTLE!!!

    hmlittle59
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2008-09-26 23:49
    Howard,

    If you're doing a layout from scratch and have the room, by all means use the larger (SOT23-size) transistors. They're much easier to see and to solder than the super teeny SOT416s!

    -Phil

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    'Still some PropSTICK Kit bare PCBs left!
  • hmlittle59hmlittle59 Posts: 404
    edited 2008-09-27 00:57
    update...

    I've ordered the parts(Digikey) and it turns out that the pinout of their components is different, that kind of confused me. Had to get help from there tech. to ensure that I knew what I was ordering. I'll just have to lay it out according to that drawing.

    The resistor pins enter and exit from the same side of the body of the chip....instead.... of enter on one side and exit on the other side of the body as in the BS2 Schematic drawing...(Across the Base)...Hope this will not be a problem(noise,feed back..etc.)

    thanks for all the help

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    I HAVE LEARN SO MUCH...BUT STILL KNOW SO LITTLE!!!

    hmlittle59
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2008-09-27 05:53
    Howard,

    Don't go by the BS2 schematic. There's an error in the pinout for the dual NPN module. Logically, it's okay (i.e. bases connect to SIN and ATN, both emitters to Vss, collectors pulled up and connected to the PIC). It's just the pinout that's wrong.

    -Phil
  • Tracy AllenTracy Allen Posts: 6,666
    edited 2008-09-27 21:03
    Note that in the dual pack, the two NPN emitters are tied together and to Vss, so it is possible to buy the version of the circuit that comes in a 5 pin package. That is, if you have the flexibility to choose your own layout. It is the logic and the ratio of resistor values that matter. The 5 pin version is nice for assembly, because there is less chance to get it in backwards!

    It is also worth mentioning, if you are building your own BS2, to watch the pinout of the PIC16F57. The pinout on the DIP and SOIC packages are different from the pinout on the SSOP package. It is the SSOP that is used on the BS2 module. The same thing is true of the 28 pin SX chip that is found on the BS2e and BS2sx. The DIP and SSOP pinouts are different.

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    Tracy Allen
    www.emesystems.com
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2008-09-27 21:13
    Tracey Allen said...
    The 5 pin version is nice for assembly, because there is less chance to get it in backwards!
    Very true. But with the six-pin version, it doesn't matter if it's backwards: it's axially symmetrical! smile.gif

    -Phil
  • Tracy AllenTracy Allen Posts: 6,666
    edited 2008-09-28 00:31
    Ahhh. It is a rare chip that is so symmetrical! I just used a BF862 jFET in a project, and it is one of those for which source and drain are interchangeable. Helps the layout options.

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    Tracy Allen
    www.emesystems.com
  • hmlittle59hmlittle59 Posts: 404
    edited 2008-10-01 20:11
    Hello Tracy / Phil,

    The parts from digikey should be here today and they are the six pin. I'm doing my own board layout and wanted to use the same board for the BS2 and BS2e but noticed the on-board 5v reg. part is different. So I may just do the "e" version and up date the code with more options.

    I'm not quite clear on the Parallax schematic layout error and the difference between 5 or 6 pin transistor. The "Dual" from Digikey is laid out differently then the Parallax Schematic, will that just complicate it even more with the pin out being wrong? Is it documented some place on this forum so I can print it out?

    1) Who has the correct pin lay out?
    2) Can I just use the Digikey part and be ok(with the correct pin out)?

    3) Why is the BS2 board different then the "e" version (5v reg.)

    I'm getting cross Eyed again on try to figure this out...thanks guys for all the help

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    I HAVE LEARN SO MUCH...BUT STILL KNOW SO LITTLE!!!

    hmlittle59
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2008-10-01 20:25
    Just ignore the erroneous pin layout in the BS2 schematic. It's irrelevent. Use the pinout from the datasheet for the part you're getting from DigiKey.

    -Phil

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    'Still some PropSTICK Kit bare PCBs left!
  • hmlittle59hmlittle59 Posts: 404
    edited 2008-10-02 00:36
    Hello Phil,

    I got my parts in today and I guess I'm still confused on how to route the traces, I have no documentations only the BS2 printout from Parallax. I have no written info on how the "Dual" transistor should be connected. I'll see if I can get it from Parallax. Thanks for the info.

    1) So I'm clear, the BS2 schematic from Parallax is wrong?


    thanks

    :

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    I HAVE LEARN SO MUCH...BUT STILL KNOW SO LITTLE!!!

    hmlittle59
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2008-10-02 00:43
    Parallax's BS2 schematic is logically correct, as far as what gets connected to each transistor's emitter, base, and collector. But the pinout (i.e. where each connection exits the package) shown for their 6-pin device is wrong. So use their schematic for the logical connections, and the datsheet for the transistor array (that you downloaded from DigiKey — right?) for the correct pinout.

    -Phil
  • hmlittle59hmlittle59 Posts: 404
    edited 2008-10-02 02:55
    I'm back, had to make a hospital run to see my father in-law who should be getting out tomorrow. Anyway I think I understand what you saying.

    I'll start on that part tomorrow. I may need to PM you if I draw a blank over night.

    thanks again

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    I HAVE LEARN SO MUCH...BUT STILL KNOW SO LITTLE!!!

    hmlittle59
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2008-10-02 05:02
    Please do not use PM or email. I won't answer there. We can continue the discussion here in the forum, if necessary, so everyone can benefit.

    -Phil
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