VARIABLE OUTPUT VOLTAGE CHARGE PUMP AND MEMS MICROPHONE APPARATUS USING SAME

摘要

The MEMS microphone apparatus of the present invention comprises: a microphone chip in which are formed a MEMS diaphragm and a back plate; and a signal processing chip comprising a variable output voltage charge pump part outputting a variable output voltage for biasing between the MEMS diaphragm and the back plate, a detection part for outputting a detection signal upon detecting electrostatic capacitance variation between the MEMS diaphragm and the back plate according to external sound-wave vibration, and an amplification part for outputting a microphone output signal obtained by amplifying the detection signal. Here, the variable output voltage charge pump part can operate so as to output the variable output voltage by boosting a power supply voltage while being activated in accordance with a predetermined voltage selection signal and reference voltage that accord with the design characteristics of the MEMS diaphragm and the back plate.