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Electronics => Beginners => Topic started by: Camelkos on September 29, 2020, 09:07:45 pm

Title: Capacitive Coupling Noise Equation
Post by: Camelkos on September 29, 2020, 09:07:45 pm

Hi Everybody,
Can someone please explain how we get this equation, frome this circuit thank you very much!!

Title: Re: Capacitive Coupling Noise Equation
Post by: drdm on September 30, 2020, 01:55:36 pm

C_1G does not play any role since it is connected directly to an ideal voltage source.
The rest of the components form a voltage divider. Upper part of the divider is C₁₂. The lower part is the parallel of C_2G and R.
If you represent R by Z_R and 1/jwC with Z_C you will have:
Vn=Vi(Zr//Zc2g)/((Zr//Zc2g)+Zc12)
The rest is a page of algebra which I'll leave to you.  :)

Title: Re: Capacitive Coupling Noise Equation
Post by: Camelkos on September 30, 2020, 09:27:31 pm

i think there's something wrong in what you wrote, can you please correct the equation

Title: Re: Capacitive Coupling Noise Equation
Post by: drdm on October 01, 2020, 08:18:28 am

Here you have the complete solution.
It could be shorter, I suppose.  :)

Title: Re: Capacitive Coupling Noise Equation
Post by: Camelkos on October 01, 2020, 08:39:35 am

Thank you very Much !!