[sdiy] What do people use for matched transistors these days?

Mike Bryant mbryant at futurehorizons.com
Fri Sep 15 20:52:21 CEST 2023

Odd.  I took one apart some years ago (when it was still NXP) and you could see it was two transistors on a single die.  Different part number but I suppose using single transistor die saves a processing step to isolate the transistors and that is more expensive then the extra pick and place step at packaging.

But provided they are from the same wafer, and will probably be from the same part of the wafer in fact, then they still should be well matched.  You wouldn't program the pick and place to take die randomly.
From: Neil Johnson <neil.johnson71 at gmail.com>
Sent: 15 September 2023 17:51
To: Mike Bryant <mbryant at futurehorizons.com>
Cc: SDIY List <synth-diy at synth-diy.org>; Scott Bernardi <scottbernardi55 at gmail.com>
Subject: Re: [sdiy] What do people use for matched transistors these days?


Mike Bryant wrote:
> Nxperia also do dual transistors without the base resistors e.g. BC856S.  They are on the same die so will be well matched.

Umm, no, they're not, according to Nexperia:

"these dual are all 2 die solution where we take them from the same wafer.
No plans to develop these parts using a single die unfortunately since
the main goal is to maximize volumes of the single die version."

A shame as it would be a great option to replace the long-gone
2SC1583, etc.  I remember years ago asking Philips about the PUMX1 and
got a similar response:

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