pn diode work
The term diode denotes a two-electrode device. A semiconductor diode is simply a P-N junction with connecting leads or terminals on the two sides of the P-N junctions.P-N junction is also called the crystal diode because the P-N junction is grown out of crystal. A diode is a unidirectional device permitting the easy flow of current in one direction but restraining the flow in opposite direction. A major application of diode is in rectification i.e., in conversion of ac into dc.semiconductor diode is becoming more and more popular these days due to its smaller size,cheapness,robustness and higher operating efficiency .
The p-type material of the diode is the positive electrode and is called the anode whereas the N-type material is the negative electrode and is called the cathode. the arrow symbol used for the anode represents the direction of flow of conventional current. the electrode current flows in a direction opposite to the arrow.
The symbol for semiconductor diode in shown in figure Diodes have polarity and, therefore,must be connected in circuits in the correct direction.small diodes are marked with a band to indicate the cathode end. larger diode use the diode symbol to indicate their polarity.Diode are available in many package configuration,depending on their ratings.small diodes,used for low current application in circuits up to 1 A of average current,are generally packaged in a simple glass r plastic tube.Diodes for handling larger currents are packaged in metal containers and are often mounted by studs on metal plates to dissipate heat.
Diodes are rated in terms of their peak and average forward current-carrying capability and in terms reverse voltage or peak inverse voltage ratings.None of these values can be exceeded,otherwise the diode will get damaged. For the P-N diode junction,the reverse voltage rating applies to the instantaneous peak reverse voltage across the diode.
the diode junction can be viewed as an automatic switch that is closed when the p-type material is relatively negative .Remember,it is the voltage across the diode that is important not the voltage to another part of the circuit. because the depletion region is never completely absent,it takes a small voltage across a diode to make current flow,even when the polarity is correct for flow of larger current..
most diodes in use today make use of silicon semiconductor material;however,for some application, germanium is also used.
pn diode work in forward wise.when p terminal is connect to positive side of battery and n terminal is connect to a negative side of battery this is called a forward wise and it is active region. pn diode when on reverse wise then it got to saturation region.
Three type of region in pn junction diode:
The term diode denotes a two-electrode device. A semiconductor diode is simply a P-N junction with connecting leads or terminals on the two sides of the P-N junctions.P-N junction is also called the crystal diode because the P-N junction is grown out of crystal. A diode is a unidirectional device permitting the easy flow of current in one direction but restraining the flow in opposite direction. A major application of diode is in rectification i.e., in conversion of ac into dc.semiconductor diode is becoming more and more popular these days due to its smaller size,cheapness,robustness and higher operating efficiency .
The p-type material of the diode is the positive electrode and is called the anode whereas the N-type material is the negative electrode and is called the cathode. the arrow symbol used for the anode represents the direction of flow of conventional current. the electrode current flows in a direction opposite to the arrow.
The symbol for semiconductor diode in shown in figure Diodes have polarity and, therefore,must be connected in circuits in the correct direction.small diodes are marked with a band to indicate the cathode end. larger diode use the diode symbol to indicate their polarity.Diode are available in many package configuration,depending on their ratings.small diodes,used for low current application in circuits up to 1 A of average current,are generally packaged in a simple glass r plastic tube.Diodes for handling larger currents are packaged in metal containers and are often mounted by studs on metal plates to dissipate heat.
Diodes are rated in terms of their peak and average forward current-carrying capability and in terms reverse voltage or peak inverse voltage ratings.None of these values can be exceeded,otherwise the diode will get damaged. For the P-N diode junction,the reverse voltage rating applies to the instantaneous peak reverse voltage across the diode.
the diode junction can be viewed as an automatic switch that is closed when the p-type material is relatively negative .Remember,it is the voltage across the diode that is important not the voltage to another part of the circuit. because the depletion region is never completely absent,it takes a small voltage across a diode to make current flow,even when the polarity is correct for flow of larger current..
most diodes in use today make use of silicon semiconductor material;however,for some application, germanium is also used.
pn diode work in forward wise.when p terminal is connect to positive side of battery and n terminal is connect to a negative side of battery this is called a forward wise and it is active region. pn diode when on reverse wise then it got to saturation region.
Three type of region in pn junction diode:
- active region
- saturation region
- cut-off region
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| picture of a diode a diode there are two terminal anode and cathode͢ gray line is cathode and all black area is anode |
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