Another one but the same topic...

Ok. So this is another one. And it's under the same topic. But i written it on the other pages..
So here it is:

Topic: PN Junction Diodes = Fundamentals of Semiconductors

'N' type semiconductor- Antimony
'P' type semiconductor - Gallium
*Electrons on the outmost shell known as valence electrons
* Arsenic is a pentavalent impurities
* For a 'p' type semiconductor the majority carriers are holes
* The process of adding controlled amount of impurities to a pure semiconductor to improve conductivity is called "Doping".
*Intrinsic semiconductors do not contain any impurities.
* Valence electrons are electrons found in the outermost shell
*ION is positively charged.
*Forward bias of an PN junction diode = the potential of the external supply forces will make holes and electrons to cross the junction.
*Diode forward characteristic curve = the forward bias resistance of the diode is very low.
* Reverse bias = the external voltage supply causes the majority carriers to move away from the junction.
* The reverse bias resistance of the diode is very high.
* The Peak Inverse Voltage is the maximum reverse voltage a diode can handle.

Diode Forward Bias Characteristic Curve and Reverse

* Break Down voltage

* For any diode, the Peak Inverse Voltage (PIV) is the maximum safe reverse voltage of a diode specified by the manufacturer .

Characteristics of a diode

* When the diode is forward biased ,  it act as a closed switch in series with a small forward voltage(0.7v).

Full-Wave Bridge Rectifier

*Requires a non-center tapped transformer and 4 diodes.

Current Relationship in a transistor

* The base current IB is very small but very important.

*Current gain= a= IC/IE

*Current gain, beta = B= IC/IB

Transistor as a switch

*Saturation - closed switch

*In saturation, base -emitter junction is forward biased and collector base junction is reverse biased.

*Large IB causes IC to reach its saturation value.

*Cut off - Open switch

*Base emitter junction is not forward-biased.

*All currents are zero.

*VCE = VCC

Safety precautions!

Important!

*Use IONIZERS to reduce charges.

*STORE and transport sensitive devices in ESD protection packaging

* Use treated plastics.