Silicon Resonator Micro-Anchor Thermal Expansion Differential Sensitivity
Micro-anchor thermal expansion differential sensitivity measures resonant frequency shifts caused by package-induced mechanical strain across temperature gradients.
Differential Sensitivity
Performance Metric
Operational response represents the change in output per unit of change in the stimulus across two distinct sensing elements. A differential sensitivity calculation minimizes common mode errors such as temperature fluctuations or supply voltage noise. By subtracting the signals of two matched sensors, the system isolates the intended physical quantity.
This method relies on the symmetry of the transducers to ensure that external interferences cancel out effectively.
Measurement Accuracy
Deviations from the ideal zero-point balance occur when the sensing elements are not perfectly matched. The accuracy of differential sensitivity depends on the ratio of the individual sensitivities and their relative offset. Thermal gradients across a substrate often introduce a localized bias that the differential circuit cannot fully eliminate.
Calibration procedures typically involve nulling the output at a reference condition to establish a stable baseline. In many industrial applications, the signal conditioning electronics include an adjustable gain stage to compensate for these initial manufacturing tolerances.
Calibration Interval
Long-term stability is influenced by the aging of the components. Drift in the differential sensitivity profile might indicate a degradation of one sensor relative to its pair. Regular verification against a known standard ensures that the gain remains within the specified tolerance.
If the mismatch exceeds the guard band, the device requires a digital or analog adjustment to restore linearity.
Drift Source
Mechanical stress on the package often induces a parasitic signal. Packaging effects can alter the piezoelectric or resistive properties of the silicon. Such shifts change the way the differential sensitivity responds to the input variable.
Guarding against these stresses involves careful selection of potting compounds.