Design of high accuracy power scalable MEMS sensor interface.

摘要

A technique to improve power scaling efficiency of automotive MEMS pressure sensor interfaces is presented. The overall power consumption of the interface is inversely proportional to the square of the amplitude and directly proportional to the input bandwidth. Power scaling with respect to amplitude is achieved by using a novel technique of cascading gain stages through an input gain-select mux, which scales better than previous approaches. Power scaling with respect to input bandwidth of the sensor is achieved through periodic power-down of the interface. A prototype of the interface was fabricated in a 1.8V, 0.18mum CMOS process. Its power consumption scales between 4muW -- 5.33mW , while maintaining a Spurious Free Dynamic Range (SFDR) range of approximately 72 -- 92dB, a Total Harmonic Distortion (THD) range of 70 -- 90dB, and an input referred noise of 170.0nV/ Hz .