ECE Dept Engineering Topics List

Subject and UNIT: Electronic Devices and Circuits: Unit I: Semiconductor Devices

In ordinary PN diode, the doping is light. So, the breakdown voltage is high. If the P and N regions are heavily doped, then breakdown voltage can be reduced.

Full wave Bridge Rectifier

Subject and UNIT: Electronic Devices and Circuits: Unit I: Semiconductor Devices

Full wave rectifier converts an ac voltage into pulsating dc voltage during both half cycles of the applied voltage.

Half wave Rectifier

Subject and UNIT: Electronic Devices and Circuits: Unit I: Semiconductor Devices

A rectifier is an electrical device that converts alternating current (ac), which periodically reverses direction to direct current (dc), which flows in only one direction. This process is called as rectification.

Derivation, Applications | PN Diode

Subject and UNIT: Electronic Devices and Circuits: Unit I: Semiconductor Devices

The capacitance which exists in a forward biased junction is called diffusion or storage capacitance

Derivation

Subject and UNIT: Electronic Devices and Circuits: Unit I: Semiconductor Devices

When PN diode is reverse biased, the majority charge carriers move away from the junction and large immobile carriers are generated near the junction. The width of the space - charge layer increases with increasing reverse voltage.

Resistance of PN Diode, Temperature Dependence of PN Diode

Subject and UNIT: Electronic Devices and Circuits: Unit I: Semiconductor Devices

When a PN diode is forward biased, the depletion region is very small and large forward current flows. The holes from p side are injected to N side and electrons from N-side are injected to P side. Thus current carried by electrons carried by electrons in P-side.

Derivation

Subject and UNIT: Electronic Devices and Circuits: Unit I: Semiconductor Devices

Consider the unbiased PN junction and to know the energy band structure, we have to analyze the Fermi level of the semiconductor material.

Types

Subject and UNIT: Electronic Devices and Circuits: Unit I: Semiconductor Devices

During reverse bias, when the reverse voltage is less than breakdown voltage, the diode current is also very small due to minority carriers and almost constant at Io. When the reverse voltage is increased beyond certain limit, the diode current will be maximum.

Forward Resistance, Reverse Resistance, with Solved Problems

Subject and UNIT: Electronic Devices and Circuits: Unit I: Semiconductor Devices

An ideal diode should offer zero resistance in forward bias and infinite resistance in the reverse bias Diode behaves as a perfect conductor in forward biased condition and act as insulator in reverse biased condition.

Reverse Biased P-N Junction, PN Diode Symbol

Subject and UNIT: Electronic Devices and Circuits: Unit I: Semiconductor Devices

In unbiased PN junction, there is no flow of current, when forward bias is applied to the PN junction, the applied forward voltage creates an electric field opposite to the potential barrier.

N Type material, Operation of a PN Junction mode

Subject and UNIT: Electronic Devices and Circuits: Unit I: Semiconductor Devices

In a piece of semiconductor, one half is doped by P-type impurity and the other half is doped by N-type impurity. Thus PN junction is formed.

Intrinsic Semiconductor, Extrinsic Semiconductors, N-Type Semiconductor, P-Type Semiconductor

Subject and UNIT: Electronic Devices and Circuits: Unit I: Semiconductor Devices

Some valence electrons may acquire sufficient energy to enter the conduction band to form free electrons such electrons constitute current when electric field is applied.