Patent ID: 8582787
Filing Date: 2013-11-12
Classification: G05F,H03F,H04R

Abstract:
1. A preamplifier circuit for a capacitive acoustic transducer, the capacitive acoustic transducer including a MEMS detection structure configured to generate a capacitive variation signal as a function of an acoustic signal, the preamplifier circuit comprising: an amplification stage configured to generate a differential output signal correlated to said capacitive variation signal, wherein said amplification stage is an input stage of said preamplifier circuit and includes a fully differential amplifier having first and second differential inputs and first and second differential outputs, the fully differential amplifier being configured to be connected to said MEMS detection structure and to amplify said capacitive variation signal for generating said differential output signal on the first and second differential outputs; and a reference generator circuit configured to supply a biasing quantity to the differential amplifier and to generate said biasing quantity proportional to a reference voltage that is stable in regard to temperature variations and manufacturing-process spread.