The sensor consists of a micro-machined structure on a silicon wafer. The structure is suspended by polysilicon springs which allow it to deflect in the when subject to acceleration in the X, Y and/or Z axis. Deflection causes a change in capacitance between fixed plates and plates attached to the suspended structure. This change in capacitance on each axis is converted to an output voltage proportional to the acceleration on that axis.
Ratiometric output means that the output voltage increases linearly with acceleration over the range.
- For the ADXL335, that is approximately 0v at -3G to 3.3v at +3G.
- For the ADXL326, that is approximately 0v at -16G to 3.3v at +16G.
- For the ADXL377, that is approximately 0v at -200G to 3.3v at +200G.
- For all modules, the output at 0G in each axis, is about 1/2 full-scale, or 1.65v.