1
\$\begingroup\$

I'm trying to do a simple 1 kHz, 1 V p-p sine wave amplification circuit using a TL071 or similar op-amp. The simulation is currently in LTSpice.

I've biased the VCC to half to try to achieve a good voltage swing but the waveform clips; it seems that the op-amp is amplifying my DC bias also.

I don't expect this op-amp to be rail-to-rail, of course.

First, here are the output waveforms:

enter image description here

V(out) is the small output signal, red is the AC sine wave, green is the biased waveform, centered at VCC/2.

Here's my circuit:

enter image description here

Any help? I'm new to this world of op-amps and struggling a bit.

\$\endgroup\$

1 Answer 1

Reset to default
10
\$\begingroup\$

The 'ground' on R3 becomes the 'zero reference' for the amplification. This should be connected to Vcc/2. Otherwise you will get strange results (what you are seeing).

There is some good information here about how to generate a virtual ground for this type of single-supply circuit: http://tangentsoft.net/elec/vgrounds.html

\$\endgroup\$
0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.