Modeling of CMOS integrated strain sensors and sensitivity enhanced readout architecture

Integrating sensors within a complete readout system on a single die has become essential to the More-than-Moore philosophy. Mechanical stress, as one of the physical quantities of potential interest, provides various information from simple static to dynamic load. Integration of piezoresistive elements within a complete CMOS system has been achieved in many ways, and ground-laying effects have been studied and described in detail. To bring the mechanical and electrical domains closer together, a new concept is presented that allows an analytical and simulation-based approximation of the sensors’ behavior due to applied mechanical stress as part of established concepts in electronics. It is evaluated based on measured state-of-the-art sensor implementations and used to bring up an alternative architecture with enhanced and on-the-fly adaptive sensitivity. Simulations are used to then further evaluate any model errors due to second-order effects that have been neglected within the design process.

Subjects

adjustable current mirror

integrated sensing

Piezoresistance

piezoresistivity

Sensitivity

sensor model

Sensors

Sensor systems

Strain measurement

Stress

Transducers

Transistors

DDC Class

620: Engineering

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Modeling of CMOS integrated strain sensors and sensitivity enhanced readout architecture