Electronic circuit
An electronic circuit is composed of individual
Circuits can be constructed of discrete components connected by individual pieces of wire, but today it is much more common to create interconnections by photolithographic techniques on a laminated
An electronic circuit can usually be categorized as an
Analog circuits
The basic components of analog circuits are wires, resistors, capacitors, inductors,
When the circuit size is comparable to a wavelength of the relevant signal frequency, a more sophisticated approach must be used, the distributed-element model. Wires are treated as transmission lines, with nominally constant characteristic impedance, and the impedances at the start and end determine transmitted and reflected waves on the line. Circuits designed according to this approach are distributed-element circuits. Such considerations typically become important for circuit boards at frequencies above a GHz; integrated circuits are smaller and can be treated as lumped elements for frequencies less than 10GHz or so.
Digital circuits
In
The design process for digital circuits is fundamentally different from the process for analog circuits. Each logic gate regenerates the binary signal, so the designer need not account for distortion, gain control, offset voltages, and other concerns faced in an analog design. As a consequence, extremely complex digital circuits, with billions of logic elements integrated on a single silicon chip, can be fabricated at low cost. Such digital integrated circuits are ubiquitous in modern electronic devices, such as calculators, mobile phone handsets, and computers. As digital circuits become more complex, issues of time delay, logic races, power dissipation, non-ideal switching, on-chip and inter-chip loading, and leakage currents, become limitations to circuit density, speed and performance.
Digital circuitry is used to create general purpose computing chips, such as
Mixed-signal circuits
Mixed-signal or hybrid circuits contain elements of both analog and digital circuits. Examples include
. Most modern radio and communications circuitry uses mixed signal circuits. For example, in a receiver, analog circuitry is used to amplify and frequency-convert signals so that they reach a suitable state to be converted into digital values, after which further signal processing can be performed in the digital domain.Design
Prototyping
In
Open-source tools like Fritzing exist to document electronic prototypes (especially the breadboard-based ones) and move toward physical production. Prototyping platforms such as Arduino also simplify the task of programming and interacting with a microcontroller.[6] The developer can choose to deploy their invention as-is using the prototyping platform, or replace it with only the microcontroller chip and the circuitry that is relevant to their product.
A technician can quickly build a prototype (and make additions and modifications) using these techniques, but for volume production it is much faster and usually cheaper to mass-produce custom printed circuit boards than to produce these other kinds of prototype boards. The proliferation of quick-turn PCB fabrication and assembly companies has enabled the concepts of rapid prototyping to be applied to electronic circuit design. It is now possible, even with the smallest passive components and largest fine-pitch packages, to have boards fabricated, assembled, and even tested in a matter of days.References
- ^ Charles Alexander and Matthew Sadiku (2004). "Fundamentals of Electric Circuits". McGraw-Hill.
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(help) - ^ Richard Jaeger (1997). "Microelectronic Circuit Design". McGraw-Hill.
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(help) - ISBN 9781420006728.
- ^ John Hayes (1993). "Introduction to Digital Logic Design". Addison Wesley.
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(help) - ^ "PCB Rapid Prototype". www.wellpcb.com. WellPCB. Retrieved 2017-06-01.
- ISBN 9781430244462.