[sdiy] 2164 overvoltage condition?

[David G Dixon]

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.  
 
  _____  

From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On Behalf Of Sean
Ellis
Sent: Monday, June 26, 2017 6:48 PM
To: synth-diy at synth-diy.org
Subject: [sdiy] 2164 overvoltage condition?



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?




-Sean


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