Patent ID: 8633617

Claim:
A filter circuit comprising; an input end, an output end; a voltage-current conversion unit that converts a voltage signal, supplied to the input end, to a current signal; a capacitor group comprising a plurality of sets of capacitors that receive the current signal from the voltage-current conversion unit at a plurality of equal and sequential time phases, the time phases comprising a cycle, and the number of time phases in the cycle being equal to the number of the sets; a plurality of first switches that provide the current signal to the capacitors of a first one of the sets during corresponding first time phases; a second switch that, during a second time phase subsequent to the first time phases, couples the capacitors of the first set, and adds the charge accumulated on the capacitors of the first set; and a third switch that, during a third time phase subsequent to the second time phase, couples at least one capacitor of the first set to the output end and provides the added charge to the output end, wherein: the third switch is n an OFF state during the first time phase; and the second switch is in the OFF state during the third time phase.