| 摘要 |
An interface circuit (INTC) is disclosed, adapted to connect a microphone circuit (MCD) to a preamplifier (PA), the microphone circuit (MCD) comprising a microphone (3) and at least an output node (M0, M0') and the preamplifier (PA) comprising at least an input node (10, 10') adapted to be connected to said output node (Mo, Mo') through said interface circuit (INTC). The interface circuit (INTC) comprises at least a decoupling capacitor (CDEC) for DC decoupling the input node (10, 10') from the output node (Mo, Mo'), the decoupling capacitor (CDEC) having a first end connected/connectable to the input node (10, 10') and a second end connected/connectable to the output node. The interface circuit (INTC) comprises at least one active circuit (UGAMP/- UGAMP ' ), comprising a resistor having a first connected to the first end of the decoupling capacitor (CDEC) r adapted to operatively act as a resistance multiplier and having an equivalent resistance that together with the decoupling capacitor (CDEC) defines a high-pass filter operatively connected / connectable between the microphone (3) and the preamplifier. The interface circuit comprises a biasing circuit connected to the second end of the resistor. |
