AC coupling and signal amplification using switched capacitors

Year	Description
1997	Invention patented by Lawrence D. Engh, Jung Sheng Hoei, and Vashal Sarin on September 4th, 1997. Abstract: AC coupling and signal amplification using switched capacitors. The use of a switched capacitor to simulate a resistor in amplifier coupling in an integrated circuit processing audio frequency signals avoids the need for external components, reducing cost and eliminating the need for pinouts for the external components. In a system including an anti-aliasing filter, capacitive coupling is used for coupling between amplifiers, with the gain of the second amplifier being set by a feedback capacitor between the amplifier output and its input, as sized relative to the coupling capacitor. The switched capacitor in the feedback loop of the second amplifier preferably couples the output of the anti-aliasing filter back to the amplifier input, thereby minimizing the aliasing from the capacitor switching.
Source: selected by the editor from original sources.

Invention: AC coupling and signal amplification using switched capacitors