A two-chip interface for a MEMS accelerometer

A proposed third-order noise-shaping accelerometer interface circuit enhances the signal-to-noise ratio, compared with previously presented interface circuits. The solution for the two-chip implementation is described and a novel cross-coupled correlated double sampling integrator is proposed. This scheme functions even with large parasitic capacitances between the sensor and the interface circuit. The op-amp noise is first-order shaped. Dithering circuit is also implemented on the chip, fabricated in an 1.6-/spl mu/m CMOS process.