ELIMINATION OF 3D PARASITIC EFFECTS ON MICROPHONE POWER SUPPLY REJECTION

摘要

Comprising a first node having a substantially equivalent 3D parasitic capacitance with respect to the preamplifier of the microphone package and a second node, such that any noise generated for the first node is equivalent to any noise generated for the second node, A microphone package is described. An external power source is connected to the first node and provides a bias voltage signal to the MEMS microphone package through the first node. The inverting amplifier is connected between the power supply and the second node. The third node is connected to the first node via a packaging parasitic capacitor, while the second node is coupled to the third node through an intended parasitic capacitor or an apparent capacitor. The noise coupled to the third node from the external power source is then canceled by summing the inverse power noise to the third node.