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Buffer circuits?

All,

Merry Christmas and a Happy New Year!

I was looking through some sensors on Digikey. Some of the ratings are given at a certain load. For instance, 50 mV at 1 k-ohm. If I wanted to bump this voltage a bit higher, can I use the following op amp buffer ckt?

The sensor output is connected to 1 k-ohm resistor with one resistor terminal connected to the non-inverting op amp input and the other terminal is grounded. The opamp output is looped back to the inverting input using a low loss piece of wire. The opamp output is then connected to my measurement device.

Will this type of circuit work accurately with little deviation from the original voltage input at the opamp?

I was thinking of all the losses that is encountered from the input of the opamp to its output. My main concern is that since the output deviation of the sensor only goes up to 50 mV at 1k-ohm, then noise might affect it significantly compared to a higher output voltage, right?

Thanks!

Reply to
Ron J
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Well, you said you wanted some gain, so why not use a 10 k ohm feedback resistor instead of a piece of wire? That would give you a voltage gain of

  1. The non-inverting op-amp input is often grounded through a resistance equal to the parallel equivalent of the input and feedback resistors (to minimize offset error).
Reply to
Charles Schuler

I should have mentioned that the signal is fed to the inverting input with a

1 k ohm resistor.
Reply to
Charles Schuler

Yes. at low frequencies (DC to about 1KHz is excellent) higher frequencies depend on the op-amp.

yes. you can get some gain from that buffer circuit by using a 1K resistor from the inverting input to ground an a 10K from the output to the inverting input

That'll amplify the input 11 times so your signal is 550mV want more? increase the 10K.

--

Bye.
   Jasen
Reply to
Jasen Betts

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