You sometimes see a series resistor, 1K or maybe 10K, on the input pin
of an op amp connected to a panel jack. The resistor does nothing to
change the behavior of the circuit, which is a unity-gain buffer. It
may provide a measure of protection for the op amp from static electric
charges that could enter via the jack by limiting the current that such
very high voltages might generate.
Richard Brewster
http://www.pugix.com
of an op amp connected to a panel jack. The resistor does nothing to
change the behavior of the circuit, which is a unity-gain buffer. It
may provide a measure of protection for the op amp from static electric
charges that could enter via the jack by limiting the current that such
very high voltages might generate.
Richard Brewster
http://www.pugix.com
>
> Thanks for answering the second question.
>
> As far as the buffer stage goes, even without the 1K resistor it has a
> high impedance (100K). What does the 1K resistor do? I'm guessing that
> I'd be fine without it, but I would like to employ it in other designs
> if it lends some added benefit.
>
> Thanks,
> peng
>
>
>