AC coupling network with variable attenuation

摘要

An AC coupling network has (a) a first pair of capacitances C 1 connected between the input nodes and the output nodes and (b) a second pair of capacitances C 2 cross-connected between the input nodes and the output nodes. The capacitances C 1 and C 2 are formed by sets of switched capacitors that can be configured to provide the network with different levels of attenuation while maintaining a constant AC coupling pole frequency. In particular, the sets of switched capacitors can be configured to ensure that C 1+ C 2 remains constant, while C 1- C 2 varies. The present invention enables AC coupling to be implemented without using active devices such as operational amplifiers and/or buffers.