Patent ID: 7535289

Claim:
An integrated RC filter comprising: a first capacitor, a first resistor that is coupled to the first capacitor through a first node, a signal input of the integrated RC filter being coupled through one of the first resistor and the first capacitor to the first node, an amplifier that is coupled between the signal input and the one of the first resistor and the first capacitor, having a gain factor substantially larger than unity, and an attenuator that couples the first node to a signal output, the attenuator having an attenuation factor that substantially corresponds to the gain factor, wherein: the signal input is subsequently coupled through the amplifier and the first capacitor to the first node, the first node is coupled through the first resistor to a DC reference voltage, and through the attenuator to the signal output, the amplifier is arranged to provide an output signal having an average DC output level at substantially half of a supply voltage level, the attenuator includes a buffer stage followed by a resistive voltage divider, the buffer stage includes an n-MOS transistor stage and the DC reference voltage is substantially equal to half of a difference between the supply voltage level and a threshold voltage of the n-MOS transistor stage.