Capacitor ratios can be very accurately controlled in an integrated circuit with the right sizing and layout strategies and thus they offer potential for making precision amplifiers. The good matching properties also are attractive for building filters.

A variant of this amplifier is shown in the figure. This is termed a charge-redistribution amplifier or a switched-capacitor amplifier. The switches are controlled by ϕ1 and ϕ2 which are non-overlapping clock signals. If a sinusoidal input is applied, the frequency of the two clock signals is usually much larger than the frequency of the input.

The relationship between the period of the clock signals, T, and the input frequency is shown in the figure. In this amplifier, the feedback capacitor is discharged during phase ϕ1 and charge proportional to VIN is stored on C1. At the end of phase ϕ1 this charge is sampled onto C1. At the start of phase ϕ2 this charge is transferred to CF and the output voltage becomes

Thus during phase ϕ2 the output signal is an amplified version of the input signal with gain equal to

The output signal is, however, valid only during phase ϕ2. The fact that the output is valid only during phase ϕ2 is not a major limitation and the gain can be accurately controlled with the capacitor ratio

The SC amplifier circuit of the figure works well in discrete form where the parasitic capacitors can be relatively small but in integrated form, the parasitic capacitance from the top plate of C1 also transfers charge to the output thus limiting the accuracy.

The two variants of the SC amplifier are Inverting and Non-Inverting Insensitive Switched Capacitor Amplifier.