PNOISE Analysis Noise Looks Different

Status
Not open for further replies.

pooh_bear

Newbie level 5
Joined
Nov 19, 2012
Messages
10
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,466
When I simulate a switched capacitor circuit for with PSS, PAC and PNOISE, the PNOISE does not come out right.

I was expecting the output noise to be 4KT(1/(f*C)) just like it would be a for a continuous time RC filter.

Rswitch = 0.01 + 10 Ohm (noise generation is enabled for each resistor)
Fsw = 1MHz
Cfly = 1pF
Cout = 8pF

If I have a continuous time RC I get the expected noise :
R = 1MHz
Cout = 8pF
Vn^2/Hz = 16f V^2/Hz

I am getting pnoise values that don't make sense. It does not come out to be the 16f V^2/Hz value and there is a lower frequency conent that creeps up.

Any help is appreciated. Thanks~
 

Attachments

  • EDA_Questions_Schematic.PNG
    14.5 KB · Views: 116
  • EDA_PAC_PNOISE_Result.PNG
    142.3 KB · Views: 151
  • EDA_Questions_PSS.PNG
    39.4 KB · Views: 114
  • EDA_Questions_PNOISE.PNG
    44.9 KB · Views: 156

Status
Not open for further replies.

Similar threads

Cookies are required to use this site. You must accept them to continue using the site. Learn more…