PASSIVE SWITCHED-CAPACITOR FILTERS

摘要

A passive switched-capacitor (PSC) filter (200) includes (i) an array of capacitors (224, 234, 244) and (ii) an array of switches (232, 242) that can couple the capacitors to a summing node (A). Each switch (232, 242) couples an associated capacitor (224, 234, 244) to the summing node (A) when enabled. Each capacitor (224, 234, 244) stores a voltage value from the summing node (A) when selected for charging and shares electrical charge with other capacitors (224, 234, 244) via the summing node (A) when selected for charge sharing. The PSC filter (200) may include multiple sections (220, 230, 240) for multiple filter taps having one or more capacitors (224, 234a, 234b, 242a, 242b, 242c) of equal size determined based on a corresponding filter coefficient. The capacitors in each section may be sequentially selected for charging or sharing electrical charge.