<title>Silicon accelerometers: generic design and operating principles and a case study</title>

Abstract

The generic design and operating principles of acceleration sensors are reviewed in terms of three partial transfer functions. An accelerometer's mechanical transfer function describes the conversion of an applied acceleration input into mechanical stress and strain in structural elements. Its electromechanical transfer function describes transduction of these elementary quantities of the mechanical energy domain into elementary quantities of the electrical domain. The electrical transfer function describes conversion of the elementary electrical quantities into an electrical output signal. The generic design issues and principles are highlighted for each of the partial transfer functions, within the boundary conditions of silicon implementations and against the widely varying background of diverse application areas. The case study of a bulk micromachined uniaxial capacitive micro-accelerometer illustrates a reduction to practice and demonstrates how accelerometer performance specifications are translated into silicon, based on the generic design principles.