Fundamentals of Electronic Components: Diodes, Semiconductors, and ICs
What is a Diode and How Is It Formed?
A diode is an element that controls the passage of electric current, allowing it to flow in only one direction. It is formed by the junction of two semiconductor crystals: an N-type cathode (electron-donating) and a P-type anode (electron-accepting).
Reverse Bias in a Diode
In reverse bias, a diode behaves as an insulator, blocking current flow. The negative pole of the power supply is connected to the anode, and the positive pole is connected to the cathode. A resistor is typically inserted in series with the diode.
What Are Semiconductors?
Semiconductors are components that act as conductors at high temperatures and as insulators at low temperatures. They can be:
- Intrinsic: Formed by silicon or germanium.
- Extrinsic: Formed by silicon or germanium with arsenic or boron.
Forward Bias in a Diode
In forward bias, a diode acts as a conductor. The positive pole of the power supply is connected to the anode, and the negative pole is connected to the cathode. A resistor is typically inserted in series with the diode.
Capacitor Function and Measurement
A capacitor is an electrical component comprising two separate conductive plates separated by a small distance and a dielectric. Its function is to store electric charge. The insulator between the plates is called a dielectric. Capacitance is measured in farads (F). Smaller units include picofarads (10-12 F), nanofarads (10-9 F), and microfarads (10-6 F).
Coil Construction and Inductance
A coil is constructed by winding a wire around a cylinder (air, metal, or ferrite core). It opposes changes in current due to the magnetic field it creates. Greater opposition indicates higher inductance, measured in henrys (H). Smaller units include microhenries (10-6 H) and millihenries (10-3 H).
What is an Integrated Circuit (IC)?
An IC is a plastic support containing a microchip connected to a larger circuit and other electronic devices. Millions of different ICs exist, identified by letters and numbers on the plastic casing.
Planar Technique and Chip Technology
Robert Noyce established the planar technique. A chip is a miniature circuit replacing numerous electronic components.
Printed Circuit
A printed circuit is the support for electronic components and their connections.
Planar Technique Process
The planar technique involves using thinly sliced P-type silicon wafers subjected to photolithography. Photographic films create masks for printing the chip design. Each mask is superimposed to create the chip’s layers.
IC Identification
Integrated circuits are identified by letters and numbers engraved on their plastic casing.
First Chip
Jack S. Kilby built the first chip in 1958.