Noise simulation in cadence

[ccw27]

How do I simulate noise in cadence? What do I use for output probe instance and what do I use for input probe instance?

Thanks

 

[terryssw]

Output probe instance is used for measuring the output noise that you are interested in. You can change it to voltage item then you just need to specified the positive and negative output node. Similarly, Input probe is used when you want to calculated also the input referred noise, and you can choose voltage type but put a voltage source to specify it. If you don't want to calculate the input referred noise, just put the input probe anywhere.

 

[gunturikishore]

Actually I had the same problem with the noise analyis. It is not accepting any source as input source. Place a 'port' instance from the anlogLib library at the input where you want to analyse noise. Try this.

 

[layes2]

use .noise to simulate it

 

[ccw27]

Yea its not allowing me to use dc voltage source as my input, you need to use port as the input. But port has 50 ohms resistance, is that ok?

Thanks

 

[gunturikishore]

I can not say that exactly.That you should decide after seing the input impedance looking into the circuit from where you are connecting the port for noise analysis. If your input impedance is too low and comparable to 50 Ohm may be you ned to change the resistance..

 

[rfsystem]

If you doing noise analysis following a linear AC analysis you could use every voltage source type. If you use a periodic noise analysis you could use port and sine sources but nor dc sources.