Patent ID: 8965013
Filing Date: 2015-02-24
Classification: H03F,H04R

Abstract:
1. A microphone system comprising: a microphone circuit comprising: a first transistor, wherein a gate terminal of the first transistor is connected to a ground terminal via a microphone electret element, the microphone electret element being associated with a capacitance and a voltage, the microphone electret element reverse biasing the first transistor; and a second transistor in parallel with the first transistor, wherein a gate terminal of the second transistor is connected to the ground terminal via a capacitor, the capacitance of the capacitor being selected to suppress at least a portion of a common mode signal, the common mode signal being at least a part of a voltage signal between a drain terminal of the first transistor and the ground terminal, and the gate terminal of the second transistor not being connected to the microphone electret element.