Operational Amplifiers and Filtering

This chapter is about the operational amplifier or op amp. The op amp is used extensively in bio–related applications to interface transducers and provide active filtering. We begin the chapter exploring op amp origins and development. We then describe the ideal op amp and use it as a benchmark for real world, nonideal op amps. We investigate how to compensate for nonideal op amp parameters. Next, we review common op amp circuit configurations used extensively in instrumentation applications. We use the circuit configurations to explore transducer interface and active filter applications. We conclude the chapter by investigating the need for instrumentation and isolation amplifiers. We close with an application related to the electrocardiogram (ECG)–a single lead heart rate monitor.