First see if you can understand the simplest switched capacitor resistor emulation as shown in this figure.
During Phase 1, the charge stored on the capacitor is V(1)*C= Q(1)
During Phase 2, the charge stored on the capacitor is V(2)*C= Q(2)
The change in charge, DeltaQ is Q(2) - Q(1) = C[V(2) - V(1)] or C*DeltaV
That change in charge occurs over the cycle of Phase 1 and Phase 2.
The period of Phase 1 and Phase 2 cycle is T. The frequency of this repetition is F=1/T.
The charge that transfers between V1 and V2 is DeltaQ and it occurs over the period, T, at a frequency of 1/T.
Current is charge per unit time.
The average current. i(avg) is DeltaQ/T = DeltaQ*F = C*DeltaV*F
So we have i(avg) = C*DeltaV*F
Rearranging we have
DeltaV/i(avg) = 1/C*F = R(equivalent)
So R = 1/FC and thus depends on frequency and capacitance.
This is a valid approximation when your signal of interest is well below the sampling frequency, F.
What this shows is that you can implement an equivalent resistance with a switched capacitor!! Very amazing. James Maxwell figured this out in the 1800s!!!
Why is it so amazing? Geez...why not just use a resistor???
If you use this structure along with a fixed capacitor in a filter structure (for example), the performance is determined by CAPACITOR RATIOS and not on absolute capacitance values. Thus you can implement very precise filters in monolithic form because capacitors can be matched very precisely!!
[I have glossed over a huge body of material with a simple explanation in hopes of getting you over the hurdle of understanding switched capacitors]
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