opa320 simple op amp doesn't work

[robseb]

Hello,

I'm exploring inverting and non inverting op amp circuits

Following a book of mine, I had success with the following circuit using an lmc6001.

However, using an opa320 for example, I can't get any amplified signal out of it

As a function generator I'm using 1Khz with 100mVp

Can someone explain what's going wrong ? How to obtain 10 times the voltage of the input ?

Thank you

[johnsold]

What do you get out of the circuit? What kind of analysis are you doing?

I wonder if the large capacitors are causing problems with establishing the DC operating point. The time constant at the input is ~0.3 s and the time constant at the non-inverting input is > 1 s. Try setting the initial conditions on the capacitors to ~2.5 V.  I  do not know what the effective input impedance fo the scope is but that could make the time constant involving C1 at the output very large.

Also, read the datasheet cautions about driving capacitive loads.

Lynn

[robseb]

I can't even get it working without capacitors, and setting them to initial 2.5v didn't change anything.

In this example, function generator is set at 10kHz 100mVp amplitude 0 offset.

Here is what I get. Channel A is input RED, Channel B is output GREEN

[johnsold]

Try moving the scope connection to pin 1 of the amplifier. That way you can see what the DC operating point is.

I do not see anything obvious. 

Lynn

[kittmaster]

You need a load resistor, best position is before the cap.