Referring to FIGS. 1 and 2, the first integrator 110 may be configured to perform an adding function (represented by an adder 130) and a first integration function (represented by a first integrator circuit 145). For example, the integrator 110 may sum an output voltage from the second signal converter 125 and a voltage of the first capacitor 210.

In an exemplary embodiment, the first integrator 110 may comprise a first resistor 220, the first capacitor 210, a second capacitor 205, and the amplifier 200. As such, the sample-and-hold circuit 105 and the first integrator 110 share the first capacitor 210 and the amplifier 200—in other words, both the amplifier 200 and the first capacitor 210 are used during the sample-and-hold function performed by the sample-and-hold circuit 105 as well as during the integration function performed by the integrator 110.

The resistor 220 may be connected between the second signal converter 125 and the first plate of the first capacitor 210. In other words, the resistor 220 may be connected in series with the first capacitor 210. In addition, the resistor 220 may be connected to the first switch 225. The resistor 220 may comprise any suitable resistive element.