[sdiy] Matched Trannies

[patchell]

    The MPQ2907 is just four transistor die in one package.  They are not monolithic.
Matching is dubious, and would have to be checked.  Chances are, they will match up fairly
good if they are from the same wafer.  There is also the problem of temperature tracking.
Although, they are mounted close together, so they may end up being even better than
glueing a couple of TO92s together.

    All I can say is try it.  I was tempted at one point, but never got around to it.

Duane R Balvage wrote:

> Hello -
>
> Anyone tried the MPS (or is it MPQ?) 2907 PNP transistor array?
>
> It is 4 PNP transistors in a 16-pin DIL package. Looks like this:
>
>         +-------+
>         | *     |
>    c1   +       + e1
>         |       |
>    c1   +       + b1
>         |       |
>    c2   +       + e2
>         |       |
>    c2   +       + b2
>         |       |
>    c3   +       + e3
>         |       |
>    c3   +       + b3
>         |       |
>    c4   +       + e4
>         |       |
>    c4   +       + b4
>         |       |
>         +-------+
>
> Vceo: 40
> Min. hFE at Ic: 100 @ 150mA
> Min. ft (MHz): 200
> Collector-Emitter Saturation Voltage :  IC = 150 mA, IB = 15 mA  0.4v
>                                         IC = 500 mA, IB = 50 mA  1.6v
>
> Is this useful in expo converters? Or do you think the transistors aren't matched well
> enough?
> The should be pretty well thermally matched (encased in the same epoxy substrate...)
>
>                         -Duane
>
>
>
> --
>
>
>        "A word to the wise ain't necessary. It's the stupid ones
>                            who need the advice."
>                          - Bill Cosby
>                       ________________________________
>                      / o o oo              o ooo o   /\
>        -------------/ ////  Duane R. Balvage   //// / /---------
>                    /    _________________________  / /
>                   / // / // /// // /// // /// / / / /
>                  /___ //////////////////////////_/ /
>                  \____\________________________\_\/
>
>                      Intel Corporation, RA2-455
>                    Portland Technology Development
>        =========================================================
>
>               Phone: (503) 613-8055    FAX: (503) 613-6143
>                   E-Mail: dbalvage at ptdcs2.ra.intel.com

--
 -Jim
------------------------------------------------
* Visit:http://www.silcom.com/~patchell/
*-----------------------------------------------
*I'm sure glad Merry Christmas comes just once a year
* -Yogi Yorgensen
------------------------------------------------