Patent ID: 6683358
Filing Date: 2004-01-27
Classification: B81B,G01P

Abstract:
A silicon integrated accelerometer comprising a fixed support base, a movable seismic mass, and beams having a thin thickness connecting said support base and said seismic mass, capable of measuring acceleration by detecting mechanical stresses based on bending of said beams, said accelerometer comprising:a plurality of strain detecting elements arranged on said beams, composed of MOS (metal oxide semiconductor) transistors, for detecting said mechanical stresses; and a differential amplifier circuit, provided with a differential amplifying function, said circuit producing an output signal proportional to a differential signal due to said mechanical stresses obtained from a pair of said strain detecting elements; wherein said MOS transistors according to said pair of strain detecting elements are structured as a part of a source coupling circuit, wherein said pair of strain detecting elements is operated in saturation region so that said output signal is amplified when said pair of strain detecting elements detect said mechanical stresses as a differential mode according to a home axis direction component to which the stress is applied and so that said output signal is reduced to zero when said pair of strain detecting elements detect said mechanical stresses as a common mode according to other axis direction components to which the stress is applied.