Why I cannot use cadence calculator to plot waveform

[bhl777]

Hi All, I have simulated in Cadence for a AC response of 1mV ac input signal. The output waveform is like this
View attachment gain.bmp
I want to change it to Vout/Vin then plot it in db form. But when I click the waveform and open the calculator, it looks like this
View attachment calculator.bmp
But does not know how to use it. I checked some previous ADE manual and it seems like a little bit different from this version.
Can anyone help me about it? Thank you!

 

[Junus2012]

Hello,

I dont know about cadence coz I am using mentor graphic, any way might be the same idea

in mentor, when I want to run the AC analyses to find Vo/Vin in DC, I chose the AC signal not the sin signal. the AC signal values are oin dB.

then in the simulation AC setup, there is an option of taking the output node with respect to the AC signal wherever it is found, so the AC simulator in mentor is always takinf the transfer function from the node you want to measure to the node of the AC source

 

[pcca]

Hello,

You need to plot both waves (input and output). A simple and fast solution: select an wave (vout for example), click with the mouse right button and select calculator. The variable related with this wave is displayed. Copy this information. After that select on the wavevier the Vin waveform and sent it to calculator. So, you will have: Vin in the calculator, put "/" and paste the Vou variable. You will get the function Vout/Vin. To plot it click on the evaluation button at the calculator.

To change the axis for db: double click on the axis. A window will open. Change from "general" view to "scale" view and mark the scale options log box.

Regards.