Difference between Transient and Transient+Noise simulation

Random noise (thermal noise, flicker noise, etc.) is not considered in a "normal" transient simulation. To learn about transient noise simulation, you can for example take a look at the Rapid Adoption Kits at https://support.cadence.com/apex/articleattachmentportal?id=a1O0V000006Dd8UUAS and https://support.cadence.com/apex/articleattachmentportal?id=a1O0V000006DdEVUA0. 

Thank you Frank for your answer, you made it clear with regards to the Random noise (thermal noise, flicker noise, etc.), I will read the resources you thankfully shared with me.

Meanwhile I have other question, suppose I want to study the supply coupling noise of the supply voltage by connecting a source noise in series to the VDD of the circuit and then I will run the transient/transient+noise, is there a noise source generator in analoglib? or I have to modulate it different way to the suppy voltage

Thank you once again

Regards

Dear Senan,

Senan said:

Meanwhile I have other question, suppose I want to study the supply coupling noise of the supply voltage by connecting a source noise in series to the VDD of the circuit and then I will run the transient/transient+noise, is there a noise source generator in analoglib?

If you are studying power supply rejection, I think it might be more insightful to modulate the supply voltage (staying within the design range of the supply voltage with your modulation amplitude) than using a noise source in series with the supply voltage. In this fashion, by applying a number of frequencies, you can establish the supply sensitivity of your design metric with frequency and amplitude. Using a transient noise simulation in its default state will include the noise of all other circuit elements. I would think it might be difficult to establish how much of the noise in your metric is due to the supply only.

Senan said:

is there a noise source generator in analoglib?

I might suggest you pass an ideal current I0 through a noisy ideal resistor R0 and use a voltage controlled voltage source to drive your circuit. Set the gain of the voltage controlled voltage source to 1 with its input as the nodes between I0R0 and its output your supply voltage terminals. You can select the value of I0R0 to be your nominal supply voltage. You may choose the value of R0 based the magnitude of thermal noise you wish to apply to the supply voltage.

I hope I understood your question Senan and this helps.

Shawn

Dear Senan,

Senan said:

Meanwhile I have other question, suppose I want to study the supply coupling noise of the supply voltage by connecting a source noise in series to the VDD of the circuit and then I will run the transient/transient+noise, is there a noise source generator in analoglib?

If you are studying power supply rejection, I think it might be more insightful to modulate the supply voltage (staying within the design range of the supply voltage with your modulation amplitude) than using a noise source in series with the supply voltage. In this fashion, by applying a number of frequencies, you can establish the supply sensitivity of your design metric with frequency and amplitude. Using a transient noise simulation in its default state will include the noise of all other circuit elements. I would think it might be difficult to establish how much of the noise in your metric is due to the supply only.

Senan said:

is there a noise source generator in analoglib?

I might suggest you pass an ideal current I0 through a noisy ideal resistor R0 and use a voltage controlled voltage source to drive your circuit. Set the gain of the voltage controlled voltage source to 1 with its input as the nodes between I0R0 and its output your supply voltage terminals. You can select the value of I0R0 to be your nominal supply voltage. You may choose the value of R0 based the magnitude of thermal noise you wish to apply to the supply voltage.

I hope I understood your question Senan and this helps.

Shawn