Low power, wide range threshold acceleration sensing system

A complete threshold acceleration detection system is presented in this paper, possessing (i) an array of threshold accelerometers, and (ii) a low power interface circuit. The sensors were designed and fabricated using a modified bulk silicon dissolved wafer process. This process offers a wide latitude in sensor threshold levels, as demonstrated in the fabrication of devices, with levels of 1.5 g to 1000 g, bandwidth of 45 Hz to 40 kHz, with mass sizes ranging from 15 programs to 0.7 /spl mu/grams, and low-resistance gold-gold contacts for the switch. The interface circuit is fabricated in-house, using a standard 3 /spl mu/m, p-well CMOS process and connected to the sensor chip, in a multi-chip module. Additionally, the system employs redundancy, to improve detection accuracy and fault tolerance, which is crucial in many applications. The system also supports communication with a standard microcontroller bus, in a smart sensor environment.