Electronic Devices - Special-Purpose Diodes - Discussion
Discussion Forum : Special-Purpose Diodes - General Questions (Q.No. 30)
30.
A varactor is a pn junction diode that always operates in ________-bias and is doped to ________ the inherent capacitance of the depletion region.
Discussion:
1 comments Page 1 of 1.
Chandu said:
1 decade ago
Varactor is a pn junction diode which is used to produce capacitance.
This means, a diode is used as a capacitor (not for switching purpose) == is called a varactor.
An insulator placed between two closely spaced conductors forms a capacitor.
When a diode is in reverse biased, it forms a depletion layer (insulator) between two semiconductor materials (which are conductors by comparison).
Therefore, reverse-biased diode has some measurable amount of junction capacitance. Under normal circumstances, junction capacitance is ignored because its value is extremely low, it is low pF range.
For high frequency operation junction capacitance is extremely important.
This diode is called a varactor. It is operated in reverse biased region.
This means, a diode is used as a capacitor (not for switching purpose) == is called a varactor.
An insulator placed between two closely spaced conductors forms a capacitor.
When a diode is in reverse biased, it forms a depletion layer (insulator) between two semiconductor materials (which are conductors by comparison).
Therefore, reverse-biased diode has some measurable amount of junction capacitance. Under normal circumstances, junction capacitance is ignored because its value is extremely low, it is low pF range.
For high frequency operation junction capacitance is extremely important.
This diode is called a varactor. It is operated in reverse biased region.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers