Smart Sensor Systems

3

Silicon Sensors: An Introduction

Paddy J. French

3.1 Introduction

In the last 30 years, silicon sensors have been able to benefit from huge price/performance improvements in the IC industry. One of the problems facing sensors compared with standard ICs is that the volume is often smaller. Although millions of pressure sensors are produced each year, they are designed for numerous applications that have many pressure ranges. Despite these problems, silicon sensors are now finding a growing market leading to reduced unit costs.

Sensors form only one part of the total system and it is essential that all components function correctly to have a useful system. Figure 3.1 shows these components. On the left-hand side is the input transducer, or sensor. The signal is often not in a desired form and can also contain cross-sensitivities. The modifier needs to convert this signal into the required form and, where possible, remove unwanted effects such as cross-sensitivity. Once the desired format is obtained the signal can be transmitted to the outside world using the output transducer (display, actuator, storage or transmission).

3.2 Measurement and Control Systems

The name ‘information-processing system’ stands for a wide spectrum of systems which comprise computers, oscilloscopes, door locks, clinical thermometers, satellites, word processors, cash registers, automatic vending machines, slide projectors, etc. All these systems process information in one way or another. In this text we ...