#### Alles Gute

##### Full Member level 2

**bw*1.57 noise**

When calculating the thermal noise of a resistor together with capacitor:

The noise density within the bandwidth of the RC filter is proportional to R, but that the bandwidth is inversely proportional to R, so that the total noise is KT/C independent of R.

But, a capacitor always has parasitic resistance, although it may be pretty small. Does that mean the thermal noise of a capacitor is always KT/C?