+ Post New Thread
Results 1 to 5 of 5

9th December 2019, 19:35 #1
 Join Date
 Feb 2015
 Posts
 108
 Helped
 2 / 2
 Points
 1,375
 Level
 8
Bilinear switched capacitor resistor equivalent resistance
I am trying to find the equivalent resistance of the following circuit in baker's book.
How do you get the factor of 4 in the denominator? I am trying to get the answer by using the principle of transfer of charge and conservation of charge like in the case below:
https://en.wikipedia.org/wiki/Switch...citor_resistor
we can assume that the voltage on the left side of cap is Vin and on the right Vout.
during phi1 voltage across the cap is V1V2 and during phi2 voltage across cap is V2V1. So shouldn't delta q be 2C(V1V2)?
so shouldn't the answer be 1/2Cf ?

Advertisement

9th December 2019, 23:47 #2
 Join Date
 Jan 2008
 Location
 Bochum, Germany
 Posts
 46,008
 Helped
 13993 / 13993
 Points
 263,329
 Level
 100
Re: Bilinear switched capacitor resistor equivalent resistance
The capacitor is charging from ΔV to +ΔV in phase 1 and back in phase 2, total q = 4CΔV.

Advertisement

10th December 2019, 01:51 #3
 Join Date
 Feb 2015
 Posts
 108
 Helped
 2 / 2
 Points
 1,375
 Level
 8
Re: Bilinear switched capacitor resistor equivalent resistance
This is not clear.
Let say the voltage at left side is V1 and on the right V2.
When s1 is closed the voltage across C is V1V2. The charge of C is C(V1V2). Now s1 is opened and s2 is closed. The voltage across C is V2V1 and the charge on it is C(V2V1). So the charge transferred out of the capacitor should be C (V1V2)  C (V2V1) is 2C(V1V2). Why is this quantity 2C(V1V2) multiplied by 2 again?

Advertisement

10th December 2019, 10:01 #4
 Join Date
 Jul 2010
 Location
 Sweden
 Posts
 1,026
 Helped
 389 / 389
 Points
 7,656
 Level
 20
Re: Bilinear switched capacitor resistor equivalent resistance
Charge is transferred to the output also when s1 is closed. What you describe happens 2 times per clock cycle.
1 members found this post helpful.

11th December 2019, 00:42 #5
 Join Date
 Feb 2015
 Posts
 108
 Helped
 2 / 2
 Points
 1,375
 Level
 8
+ Post New Thread
Please login