tailieunhanh - Multisensor thiết bị đo đạc thiết kế 6o (P2)

INSTRUMENTATION AMPLIFIERS AND PARAMETER ERRORS This chapter is concerned with the devices and circuits that comprise the electronic amplifiers of linear systems utilized in instrumentation applications. This development begins with the temperature limitations of semiconductor devices, and is then extended to differential amplifiers and an analysis of their parameters for understanding operational amplifiers from the perspective of their internal stages. | Multisensor Instrumentation 6a Design. By Patrick H. Garrett Copyright 2002 by John Wiley Sons Inc. ISBNs 0-471-20506-0 Print 0-471-22155-4 Electronic 2 INSTRUMENTATION AMPLIFIERS AND PARAMETER ERRORS 2-0 INTRODUCTION This chapter is concerned with the devices and circuits that comprise the electronic amplifiers of linear systems utilized in instrumentation applications. This development begins with the temperature limitations of semiconductor devices and is then extended to differential amplifiers and an analysis of their parameters for understanding operational amplifiers from the perspective of their internal stages. This includes gain-bandwidth-phase stability relationships and interactions in multiple amplifier systems. An understanding of the capabilities and limitations of operational amplifiers is essential to understanding instrumentation amplifiers. An instrumentation amplifier usually is the first electronic device encountered in a signal acquisition system and in large part it is responsible for the ultimate data accuracy attainable. Present instrumentation amplifiers are shown to possess sufficient linearity CMRR low noise and precision for total errors in the microvolt range. Five categories of instrumentation amplifier applications are described with representative contemporary devices and parameters provided for each. These parameters are then utilized to compare amplifier circuits for implementations ranging from low input voltage error to wide bandwidth applications. 2-1 DEVICE TEMPERATURE CHARACTERISTICS The elemental semiconductor device in electronic circuits is the pn junction among its forms are diodes and bipolar and FET transistors. The availability of free carriers that result in current flow in a semiconductor is a direct function of the applied thermal energy. At room temperature taken as 20 C 293 K above absolute zero there is abundant energy to liberate the valence electrons of a semiconductor. These carriers are then free to drift .