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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Neil Johnson and Oscar Salas did some research and write-up:<br>
<a href="http://www.milton.arachsys.com/nj71/index.php?menu=2&submenu=2&subsubmenu=3">http://www.milton.arachsys.com/nj71/index.php?menu=2&submenu=2&subsubmenu=3</a><o:p></o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Synth-diy [mailto:synth-diy-bounces@synth-diy.org]
<b>On Behalf Of </b>Quincas Moreira<br>
<b>Sent:</b> Tuesday, June 27, 2017 6:49 AM<br>
<b>To:</b> David G Dixon <dixon@mail.ubc.ca><br>
<b>Cc:</b> synth-diy mailing list <synth-diy@synth-diy.org><br>
<b>Subject:</b> Re: [sdiy] 2164 overvoltage condition?<o:p></o:p></span></p>
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<p class="MsoNormal">Dave, you're a rock star :)<o:p></o:p></p>
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<p class="MsoNormal">Incidentally, I've heard there's a common trick with diodes done in most designs to protect the 2164 from frying by getting power on one rail before another (or something like that). Can somebody explain that better to me?<o:p></o:p></p>
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<p class="MsoNormal">On Mon, Jun 26, 2017 at 11:42 PM, David G Dixon <<a href="mailto:dixon@mail.ubc.ca" target="_blank">dixon@mail.ubc.ca</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal"><span class="m4864580003579947465857172704-27062017"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:blue">You should also realize that the 2164 is a current amp. I know that the datasheet says that the absolute maximum
voltage of the input is the rail voltage, but one never feeds a voltage source directly to 2164. One drops the voltage across an input resistor (usual 30k) because the input pin is at virtual ground. Hence, assuming a +15V supply, the largest current the
input pin ever sees is about 500uA. If the rail is connected directly to the input pin, who knows what the input current is -- possibly enough to fry the chip, I guess.
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<p class="MsoNormal" style="margin-bottom:12.0pt"><b><span style="font-size:10.0pt;font-family:"Tahoma",sans-serif">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma",sans-serif"> Synth-diy [mailto:<a href="mailto:synth-diy-bounces@synth-diy.org" target="_blank">synth-diy-bounces@synth-diy.org</a>]
<b>On Behalf Of </b>Sean Ellis<br>
<b>Sent:</b> Monday, June 26, 2017 6:48 PM<br>
<b>To:</b> <a href="mailto:synth-diy@synth-diy.org" target="_blank">synth-diy@synth-diy.org</a><br>
<b>Subject:</b> [sdiy] 2164 overvoltage condition?</span><o:p></o:p></p>
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<p><span style="font-family:"Calibri",sans-serif;color:black">I've been breadboarding a filter and oscillator using a single 2164 and I think I just fried my only 2164 on hand. I have the power supply protected but accidentally put -12 straight into the input
of one amp (the control pin was at about 2.5V) and suddenly it died. The datasheet specifies the max ratings to the supply rails so I don't get why it could have (seemingly) destroyed the chip. Could it maybe have caused excessive heat?<o:p></o:p></span></p>
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<p><span style="font-family:"Calibri",sans-serif;color:black">-Sean<o:p></o:p></span></p>
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<p class="MsoNormal">-- <o:p></o:p></p>
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<p class="MsoNormal">Quincas Moreira<br>
Test Pilot at VBrazil Modular<o:p></o:p></p>
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