LM5122: Spectrum analyzer in and common chokeTINA-TI

Alex Vasin

Prodigy 155 points

Part Number: LM5122
Other Parts Discussed in Thread: TINA-TI

How to convert dBV to dbµV in the spectrum analyzer.

And I need to add to the model common mode choke from here:www.we-online.com/.../. How can I do this?

over 5 years ago

0 Youhao Xi over 5 years ago

TI__Guru* 78270 points

Hi Alex,

Add 120 to the dBV curve, then you get the curve showing in dBuV. Or, you amplify the original signal by 10^6 before processing dB.

Thanks,

Youhao Xi, Applications ENgineering

0 Alex Vasin over 5 years ago in reply to Youhao Xi

Prodigy 155 points

Hi, Youhao

Please explain in more detail how to do this in TINA-TI. How add 120 to the dBV curve?

And what about common mode choke? I downloaded it from here https://www.we-online.com/catalog/en/WE-CMB/. How do I add it to TINA?

0 Youhao Xi over 5 years ago in reply to Alex Vasin

TI__Guru* 78270 points

You can use use a voltage controlled voltage source with gain of 10^6 to generate an amplified signal of the voltage that you want to measure, then measure that in dBV scale but the curve actually represents dBuV.

Thanks,

Youhao

0 Alex Vasin over 5 years ago in reply to Youhao Xi

Prodigy 155 points

Hi, Youhao
Please explain how to do this in the program, which buttons to press?
I can't understand this.LM5122_with_LISN_rev5.TSC

0 Youhao Xi over 5 years ago in reply to Alex Vasin

TI__Guru* 78270 points

Hi Alex,

I never used the signal analyzer of the TINA, and I could not find how to open up the analyzer as you did. However, the concept should work: in the circuit, for instance, you want to analyze the voltage node of Vanalyzeru1. Add a voltage controlled voltage source (VCVS), set the gain to 1MEG, or 10^6, then, use the analyzer to process the resulted voltage of this VCVS, and what you got is equivalent to dBuV.

I updated your schematic. Analyzing the node voltage VuV from the VCVS should be equivalent to dBuV in the scale of dBV.

8272.LM5122_with_LISN_rev5.TSC

Thanks,

Youhao

0 Alex Vasin over 5 years ago in reply to Youhao Xi

Prodigy 155 points

What about reference window?

Perhaps this is the setting that will allow you to convert dBV to dBμV. Am I right?

0 Youhao Xi over 5 years ago in reply to Alex Vasin

TI__Guru* 78270 points

I cannot tell because I never used this analyzer. Did you see the difference on the left window graph by changing the ref from 1V to 1uV? If you see the vertical scale changed and the reading is 120dB difference, then yes it is the way to convert to dBuV.

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LM5122: Spectrum analyzer in and common chokeTINA-TI