Motorola MMA1201P is a single-axis, surface micromachined MEMS accelerometer rated for ± 40 G and is packed in a plastic 16-lead DIP package. The operating temperature range is –40 ° C to +85 ° C with a storage temperature range of –40 ° C to +105 ° C. The part can sustain accelerations up to 2000 g from any axis while unpowered and powered accelerations up to 500 g.

The main components of the MMA1201P consist of a surface micromachined capacitive sensing cell (g-cell) and a CMOS signal conditioning ASIC. The g-cell’s mechanical structure is composed of three consecutive semiconductor plates, defining sensitivity along the Z-axis (orthogonal to flat plane of the chip). When the accelerometer system is subjected to accelerations with components parallel to the sensitive axis of the g-cell, the center plate moves relative to the outer stationary plates, causing two shifts in capacitance, one for each outer plate, proportional to the magnitude of force applied. The shifts in capacitance are then processed by the CMOS ASIC, which determines the acceleration of the system (using switched capacitor techniques), conditions and filters the signal, and returns a ratiometric high voltage output.