APPLICATION NOTE 871

Demystifying Piezoresistive Pressure Sensors


Abstract: Monocrystalline silicon pressure sensors have come into wide use in recent years. Though manufactured with semiconductor technology, they also operate on the resistive principle. The resistance change in a monocrystalline semiconductor (a piezoelectric effect) is substantially higher than that in standard strain gauges, whose resistance changes with geometrical changes in the structure. Conductivity in a doped semiconductor is influenced by a change (compression or stretching of the crystal grid) that can be produced by an extremely small mechanical deformation. Using a signal conditioning integrated circuit to temperature compensate and amplify the signal offers superior performance over discrete circuits.