Multi-stage switched-capacitor dc blocking circuit for audio frontend

A method for driving a two-stage switched-capacitor circuit in an integrated circuit of a DC blocking amplifier, the method comprising:

• determining a first sampling frequency of a first stage of the two-stage switched-capacitor circuit to be above a minimum sampling rate for an audio signal, but at a relatively low frequency;
• determining a second sampling frequency of a second stage of the two-stage switched-capacitor circuit to be above a minimum sampling rate for an audio signal, but at a relatively high frequency;
• driving the first stage above a minimum sampling rate for an audio signal, but at a relatively low frequency;
• and
• driving the second stage above a minimum sampling rate for an audio signal, but at a relatively high frequency.

An apparatus for driving a two-stage switched-capacitor circuit in an integrated circuit of a DC blocking amplifier, the apparatus comprising:

• means for determining a first sampling frequency of a first stage of the two-stage switched-capacitor circuit to be above a minimum sampling rate for an audio signal, but at a relatively low frequency;
• means for determining a second sampling frequency of a second stage of the two-stage switched-capacitor circuit to be above a minimum sampling rate for an audio signal, but at a relatively high frequency;
• means for driving the first stage above a minimum sampling rate for an audio signal, but at a relatively low frequency;
• and
• means for driving the second stage above a minimum sampling rate for an audio signal, but at a relatively high frequency.