Junction Field Effect Transistor (JFET)
A Junction Field Effect Transistor (JFET) consists of a channel and a pn junction. The gate controls the conductance of the channel. A JFET is a voltage controlled device, therefore no current flows into the gate. More ...
EMI, RFI, EMC, EMS, What's the Difference?
EMI, RFI, EMC, and EMS all refer to different aspects of radio frequency interference which may cause elecronic devices to malfunction. Correcting these problems can be an art and a science. More ...
Alternating Current
With DC (Direct Current), electric current flows in only one direction. With AC (Alternating Current), current direction reverses periodically. More ...
Common Emitter Configuration Transistor Biasing
To design a common emitter amplifier circuit, use a voltage divider with resistors selected to set the base voltage at the center of the transistor's linear region. Then, through a DC blocking capacitor, apply a waveform to the transistor's base. More ...
Integrated Circuit Manufacturing E-Beam Lithography
Optical lithography high resolution, at low cost, but it has limitations. Electron-beam lithography uses an electron gun to generate a beam of electrons to produce submicrometer resist geometries without a mask. More ...
Inductor Mutual Inductance and Coefficient of Coupling
Mutual Inductance the property of a coil in which it opposes the change of current in another coil. The coefficient of coupling between two coils is the fraction of magnetic flux produced by the current in one coil that links with the other coil. More ...
The Diode
A diode is a semiconductor component designed to allow current to pass in one direction. To form a diode, a P type semiconductor is joined with an N type of the same semiconductor element, forming a P-N junction. Diodes are used for turning AC to DC, isolating signals, and mixing signals. More ...
Phase shift in AC Circuits
In an AC circuit with a capacitor or an inductor there is a phase shift between voltage and current. In this article you learn how to calculate the amount of that phase shift. More ...
Light Emitting Diode (LED)
An LED is a diode that converts electrical current directly into light and therefore it is more efficient than other sources of light which convert some energy into heat. When electrons recombine with holes in the depletion region they release energy in the form of light photons. More ...
Superposition Theorem
The resistive networks that satisfy Ohm's law allow a number of simplifying approaches to be taken in their analysis. Circuit analysis by superposition replaces all voltage sources but one with short circuits, then using the summation rules of series-parallel combinations of resistors determine the voltage across and current in each branch due to the remaining voltage source, and then repeating this process for all voltage sources and superposing the results. More ...
Batteries
Early in the history of electrical science, laboratory physicists found that when metals came into contact with certain chemical solutions, voltages appeared between the pieces of metal. These were the first electrochemical cells. More ...
Integrated Circuit Manufacturing CMOS Fabrication Sequence
Complementary Metal Oxide Semiconductor (CMOS) is used to fabricate digital circuits and IC chips. It is a combination of NMOS (N-type Metal Oxide Semiconductor) and PMOS (P-type Metal Oxide Semiconductor) transistor pairs. CMOS fabrication can be carried out in many ways. P-well is one of the processes in which CMOS fabrication is realized. More ...
Transforming Sources for Circuit Analysis
Kirchhoff's laws and Ohm's laws can get pretty laborious when you're analyzing complex circuits. Through a transformation technique, you modify a complex circuit so that in the transformed circuit, the devices are all connected in series or in parallel. After the transformation, you no longer need to systematically apply Kirchhoff's laws. More ...
How to Calculate Impedance
Impedance is one of the most difficult things the electronics technician student needs to calculate. To calculate impedance, you must know the value of all resistors and the impedance of all inductors and capacitors in the circuit. Then you can calculate impedance using a simple mathematical formula. More ...
