Microphone assembly with P-type preamplifier input stage

A method of processing an electrical signal from a condenser transducer element having a displaceable diaphragm and a back-plate, the method comprising the steps of:

• providing the condenser transducer element with the displaceable diaphragm operatively connected to a source input of a P-type field effect transistor;
• providing a DC bias voltage to the back-plate by a microphone bias voltage source being integrated on an electronic or integrated semiconductor circuit die together with the input stage P-type field effect transistor;
• providing an external supply voltage to the displaceable diaphragm and the source input;
• providing the condenser transducer element with the back-plate operatively connected to a gate input of the P-type field effect transistor;
• and
• processing an electrical signal provided at the drain output of the P-type field effect transistor.

An integrated semiconductor circuit comprising:

• a preamplifier circuit having an input stage comprising a P-type field effect transistor, the preamplifier circuit comprising a first externally accessible input terminal operatively connected to a source input of the P-type field effect transistor and a second externally accessible input terminal operatively connected to a gate input of the P-type field effect transistor;
• and
• a microphone bias voltage source adapted to provide a DC bias voltage to the second externally accessible input terminal so as to provide a DC bias voltage for one of the displaceable diaphragm and the back-plate, the microphone bias voltage source being integrated on an electronic or integrated semiconductor circuit die together with the input stage P-type field effect transistor,
• wherein the first and second input terminals are operatively connectable to an associated displaceable diaphragm and an associated back-plate, respectively, of a condenser transducer element, the back-plate being operatively connected to the gate input of the P-type field effect transistor, and the displaceable diaphragm being operatively connected to the source input of the P-type field effect transistor;
• and
• the displaceable diaphragm and the source input are configured to be referenced to an external power supply voltage.