AD8130 Simulation of LTSpice not meeting expected results

Hi EEEnthusiast ,

Before I properly Address this one, can you update your LTspice version to our latest one? Which is Version 24.

1. Yes, based from the datasheet, this device should suffice.

2. Have you tried adding a grounding on your supply voltages, in between your V3 and V4.

3. Yes, according to your target performance, a gain of 2 would do.

Regards,

Earl

Hi Earl,

Many thanks for your detailed response. You were correct, I did not include a grounding on my supply voltages. I have changed the circuit (below) following the datasheet configuration:

The output doesn't look too bad now. However the output amplitude is well over 5V, so I'm not sure if I configured the gain properly for a gain of 2.

Here is the output plot:

The red pulse is the output of this circuit, and the neon/cyan wave is the ideal output I am going for.

I have some additional questions:

1. How can I improve this output pulse so that it is cleaner and resembles an ideal clock pulse more?

2. Why is the output pulse over 5 V? If I have succesfully configured for a gain of 2 ? (Vout=Vin(1+ 1k/1k)) (This is not too important to me, but still I would like to know why)

3. The output pulse shows some dipping into the negative voltage range, acting almost like an alternating wave rather than a DC clock pulse. Is there any way I can eliminate this using a capacitor/etc.? 

I noticed that when I adjust the resistor values from 1k ohms to say 250 ohms each, this improves the output pulse and less of it goes into the negative voltage range. However is this recommended or a good idea? (maybe current may be too high?)

Please let me know if you are able to, what I can do to improve this output.

Any help would be greatly appreciated.

Thank you very much,

J.C.

I also updated my LTSpice version :)

HI EEEnthusiast ,

Can you share your simulation file?

So I could investigate further.

Best Regards,

Earl

Hi Earl,

Here is my file:

AD8130Sim.asc

Thanks,

J.C.

Hi Earl,

It appears I unintentionally put an unwanted voltage source way off to the left of the circuit in the file I sent earlier. Just in case you run into some error saying its value is undefined.

Thanks,

J.C.

Hi EEEnthusiast ,

I actually noticed it immediately. Although thanks for the information. :)

As a habit, when I review LTspice Simulation Files, my first action is to "zoom to fit" in my shortcut, I use "spacebar" , this allow me to see if there are floating nodes, components, sources, etc. around the schematic so I could remove it if it is unnecessary. (Just sharing)

I'd try to run and investigate your simulation file, we are just currently full on load right now, but, I'll make it a way to reply to you soonest.

BR,

earl

Hi Earl,

I appreciate it. Keep me posted on what you find.

Thank you!

J.C.