Saturday, November 15, 2014

Op-Amps in Analog Electrical Systems - Web-Based Items of Reference, with Correlated Notes

The following represents a week's survey of online resources, with regards to applications of operational amplifiers within analog electrical systems. Some additional resources are made reference to, in this article, with regards to digital electrical systems.

Ed. Note: Though the author has gone to some lengths to provide a structured reference outline, in this article, however the presentation of the article is certainly leaving something lacking, with regards to synthesis and content development. The author wishes to lend favor towards modular applications of digital electronics, in this era of contemporary microprocessor design.

With regards to physical behaviors of analog components including op-amps, in a short survey of existing knowledge, some resources may seem to suggest that an analog signal system component such as an op-amp would be inclined to demonstrate any number of nondeterministic behaviors, within an electrical system. Considering that an op-amp itself may be constructed of transistor elements, perhaps it may be possible to develop a digital analogue of any single such analog circuit, effectively as to minimize any margin of error, as in regards to circuit responsiveness in a frequency domain.

The author would not wish to trouble the reader's attention with any naive hypothesis in regards to reductive analysis of electrical circuits -- such as toward calculation of equivalent resistances, equivalent inductance, and in the domain of digital logic, DeMorgan's Theorems. Presently, this article returns to address applications in the nondeterministic analog domain, focusing on applications of operational amplifiers within analog circuits.

Op-Amp Characteristics

Op-Amp Variants

Differentiation of Op-Amp Variants

  • Voltage Feedback (VFB)
  • Current Feedback (CFB)

Applications by Variant

CFB and VFB Applications Contrasted

  • Virtual Ground Circuits, article at Tangentsoft
    • Article provides numerous examples of methods for developing a dual-voltage power supply of +/- N volts DC, from a single source voltage, including CFB and VFB applications

CFB Applications

Applications for Op-Amps - Analog Electronics

  • Sidebar: Differentiation of inverting amplifier and non-inverting amplifier applications
    • Amplifier utilizing, respectively, negative feedback or feedback from the output terminal of the op-amp, with a resistor of a calculated rating, in series to one of the input terminals of the op-amp
    • Theory of operation entails an application of qualities of electrical impedance
    • Differentiation derives from which input terminal that the resistor on the output terminal would be routed to
      • If the resistor on the output terminal is routed to the inverting input, conventional rhetoric denotes the application as an inverting amplifier
      • If the resistor on the output terminal is routed to the non-inverting input, conventional rhetoric denotes the application as an non-inverting amplifier
  • Context: Mathematical functions in amplification of analog input signals
    • Resource: Wikibooks. Op-Amp Configurations
      • Pattern: Differential amplifier
      • Pattern: Summing Amplifier
      • Pattern: Inverting Integrator
      • Pattern: Inverting Differentiator
      • Pattern: Logarithmic Output
      • Pattern: Exponential Output
      • See also: Applications of analog electrical systems in audio signal synthesis
    • Resource: Ardizzoni, John. Efficiently Design An Op-Amp Summer Circuit
  • Application: Simulated Inductor
    • Resource: Elliot Sound Products. Audio Design with Op-Amps
      • Selected Characteristics 
        • Feedback via inverting input
        • Capacitor on non-inverting input
      • Advantage: May serve to mitigate concerns with regards to EMF effects in a circuit's operational environment, as with regards to the magnetic flux  created by a conventional inductor
      • Advantage: May serve to mitigate concerns with regards to voltage spikes, as produced by conventional inductors around some events in circuit operation
  • TBD: Relevance for applications of op-amp components within digital electrical systems
    • TBD: Designs of analog-digital converter (ADC) interfaces
    • TBD: Relevance in applications of digital signal processing (DSP)
      • Application: Software analysis of radio signals
  • TBD: Functional applications of filter components in analog and digital electronics