[sdiy] double transistors

[MountainMan]

When people talk about "matching transistors", what do they mean?  How
does one determine this?

Thanks,
Elby


On Thu, 5 Apr 2001, Happy Harry wrote:

> I got some sample quad transistors from Central Semiconductor...
> a quad 2N3904 in a dip-14 package.  I need to check them for
> matching. A quick check with a Fluke 8050A looks pretty good, but that
> is at an absurdly low current level (can you say all curves meet at the 
> origin...)
> 
> A LOT of these units are NOT on the same die... they are two trannys
> in one package... they are probably sliced from the same wafer and might be 
> quite well matched by good fortune... no guarantee.
> 
> These are probably better than gluing two 2N3904 face to face though,
> unless you match them.
> 
> Hehheh  NO match for MAT-02
> 
> H^) harry
> 
> 
> 
> >From: Trevor Page <trevor at resonance.fsnet.co.uk>
> >To: harm jansen <polynipaam at yahoo.com>, synth-diy at node12b53.a2000.nl
> >Subject: Re: [sdiy] double transistors
> >Date: Thu, 5 Apr 2001 11:17:41 +0100 (GMT+01:00)
> >
> >Hi,
> >
> >Farnell stocks these components. I ordered these for exactly the same 
> >purpose (TB303 VCO, VCF) but they have been sitting on my desk for month 
> >since I've not taken the time to try them yet, so not sure how they 
> >perform. Actually, I didn't order the PUM components, but got the BC857s 
> >and BC847s instead. The PUMZ, PUMX and BC dual SMD devices are grouped 
> >together in the Farnell semi's catalogue.
> >
> >I also found Farnell's SMD tempco's useful...
> >
> >Trev
> >
> >
> >----- Original Message -----
> >From: harm jansen <polynipaam at yahoo.com>
> >To: synth-diy at node12b53.a2000.nl
> >Sent: Thu, 5 Apr 2001 10:44:06 +0100 (GMT+01:00)
> >Subject: [sdiy] double transistors
> >
> > >
> > > Hi All,
> > >
> > > While looking for double transistors I stumbled upon
> > > some SMD double transistors that seem interesting for
> > > applications where space is a problem.
> > >
> > > Philips semiconductor makes three kinds:
> > > the first device is two NPN transistors in one package
> > > the second device is two PNP transistors in a package
> > > the third device is one NPN and one PNP in a package
> > >
> > > names: PUMX1 PUMT1 PUMZ1
> > >
> > > Does anyone know which company stocks these.
> > > The only companies that I found where arrow and
> > > pioneer
> > > but the quantity that you have to take is quite large.
> > > But the price is unbelievably low $0.063. This would
> > > make the cost $189 not a lot for 3000 double
> > > transistors.
> > >
> > > Harm
> > >
> > > __________________________________________________
> > > Do You Yahoo!?
> > > Get email at your own domain with Yahoo! Mail.
> > > http://personal.mail.yahoo.com/
> >
> >
> >
> >
> >____________________________________________________________
> >Freeserve - get your free ISP service including web-mail at:
> >www.freeserve.co.uk
> >
> >
> >
> >
> 
> _________________________________________________________________
> Get your FREE download of MSN Explorer at http://explorer.msn.com
> 
>