June 6, 2021 Pointless

Testing the op amp clipper circuit

Testing my theory

Testing the op amp clipper circuit

To test my clipper design I have built the following circuit:

As you can see it a positive clipper followed by a negative clipper. The op amp used is the MAX44252 from TI. It was the fastest 4-ply op amp in my lab. I wish I had some LT6015s that Analog Devices used in their circuit. This is my test setup:

Let's go for the jugular first. How does it compare to AD's circuit at 30kH?

Analog Devices circuit @30kHz 7Vpp
Grease monkey's circuit @30kHz 8Vpp

I think it is doing better :). Let me zoom the clipping in to be more legible.

Now let's test it on different frequencies. The input signal is 8Vpp and the clipping happens at +2V and -2V.

1 kHz. Perfect.
20kHz. OK...
40kHz. Kind of OK.
75kHz. Still better than AD :)
150kHz. The op amp is trying hard to keep up... 
300kHz. I call it quits.

Just for fun I changed the op amp with a really slow LM324.

LM324 @ 3kHz. Terrible.
LM324 @ 500Hz.