<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=Windows-1252">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Diodes Inc state theirs are adjacent.</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof ContentPasted0">
"Our transistor portfolio features intrinsically matched pairs of PNP + PNP or NPN + NPN transistors, which are built with adjacent die from a single wafer. These pairs of PNP or NPN transistors are matched to a maximum tolerance of 2% for DC current gain,
hFE, VCE(sat), and VBE(sat)."<br>
</div>
<div id="appendonsend"></div>
<hr style="display:inline-block;width:98%" tabindex="-1">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Synth-diy <synth-diy-bounces@synth-diy.org> on behalf of Neil Johnson via Synth-diy <synth-diy@synth-diy.org><br>
<b>Sent:</b> 15 September 2023 19:51<br>
<b>To:</b> Pete Hartman <pete.hartman@gmail.com><br>
<b>Cc:</b> SDIY List <synth-diy@synth-diy.org><br>
<b>Subject:</b> Re: [sdiy] What do people use for matched transistors these days?</font>
<div> </div>
</div>
<div class="BodyFragment"><font size="2"><span style="font-size:11pt;">
<div class="PlainText">Pete Hartman wrote:<br>
><br>
> Hm.<br>
> - can these still apply the same logic of "two transistors on the same strip are probably close enough" ?<br>
> - I'm curious what the use case is for a dual transistor where they're not matched.... I mean these cases are a *little* smaller than two individual SOT-23's but there are also smaller packages that could be used.<br>
<br>
Yes indeed, that's one of their selling points - they'll be from<br>
similar areas on the same wafer so they're going to be quite well<br>
matched. BUT BUT BUT they are not on the same piece of silicon<br>
(poorer thermal tracking) and they are not laid out on the silicon for<br>
matching, so they'll never match (pun intended) the matching you'll<br>
get with proper matched pair devices (e.g., LM394, etc).<br>
<br>
For example, Infineon's datasheet for the BC856S says on the front page:<br>
• For AF input stages and driver applications<br>
• High current gain<br>
• Low collector-emitter saturation voltage<br>
• Two (galvanic) internal isolated transistor with good matching in one package<br>
<br>
The galvanic isolation gives the game away - there is literally an<br>
air-gap between the two transistors.<br>
<br>
If you need two transistors that are reasonably matched and reasonably<br>
thermally-linked then these devices will do the job. If you need two<br>
transistors, then putting down one part is cheaper than putting down<br>
two parts.<br>
<br>
Neil<br>
<br>
_______________________________________________<br>
Synth-diy mailing list<br>
Synth-diy@synth-diy.org<br>
<a href="http://synth-diy.org/mailman/listinfo/synth-diy">http://synth-diy.org/mailman/listinfo/synth-diy</a><br>
Selling or trading? Use marketplace@synth-diy.org<br>
</div>
</span></font></div>
</body>
</html>