Patent ID: 7046046

Claim:
A signal scaling circuit, comprising: first, second and third capacitors connected to a first node; a first switch connected between the first capacitor and a signal input; a second switch connected between the first capacitor and a reference voltage; a third switch connected between the second capacitor and the input signal; a fourth switch connected between the second capacitor and the reference voltage; a fifth switch connected between the third capacitor and the input signal; a sixth switch connected between the third capacitor and the reference voltage; a seventh switch connected in parallel with the first capacitor; an eighth switch connected in parallel with the second capacitor; a ninth switch connected in parallel with the third capacitor; a tenth switch connected between a common mode voltage source and the first node; an eleventh switch connected between the first node and an output of the signal scaling circuit; and a switch controller for controlling the first through eleventh switches, wherein the switch controller controls opening and closing appropriate ones of the first through eleventh switches so that the output of the signal scaling circuit has a second signal amplitude that is scaled to one-third or two-thirds of a first signal amplitude at the signal input.