Method and apparatus for substantially improving power supply rejection performance in a miniature microphone assembly

摘要

A hybrid circuit (300) for use in a miniature microphone assembly (100) reduces power supply noise on the audio signal input (214) of an impedance buffer amplifier (200) using one or both of shielding conductors 422, 424 to reduce parasitic capacitance between signal (418) and power supply (420) conductors. A ground plane (424), an interposing conductor (422) and combinations thereof are selectively placed and coupled to either ground (232) or a low impedance signal node (216) to reduce or eliminate the undesirable parasitic capacitance.