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When a pn junction is reversed bias practically no current flows through it ,but a very small current flows through due to minority charge carriers ,which is known as reverse saturation current .In p type due to electrons and in n type due to holes .
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What is an ideal diode?
A: That is no such a diode but if it exists it will have unlimited reverse voltage capability the forward voltage drop will be zero no matter of current flow and it will remain so regardless of temperature changes
Is zener diode an ideal current source?
A: An ideal current source can be defined as a short with immense current capabilities A zener has no such capabilities
Why there is no current in reverse bias condition?
Current flows in a reverse biased diode because diodes are not ideal. They do have leakage current and a breakdown voltage in reverse, just as they have a breakdown current in forward and a non-linear and non-parallel forward voltage to current curve. It is also possible that you are looking at a zener diode. A zener diode is specifically design to conduct at a certain voltage in reverse.
How is zener diode different from ordinary pn junction diode in its fabrication?
An ideal zener diode will have zero reverse current while the reverse voltage is less than the zener voltage. Once the voltage rises above the zener voltage, the maximum reverse current will become infinite (the device will become a short). On a graph with voltage along the X axis and current along the Y axis, this would be represented by a straight vertical line crossing through the zener voltage. A practical zener diode has a monotonic change from zero current at zero volts, rising gradually as the voltage approaches the zener voltage from below, then rising sharply as the voltage is around the zener voltage. This means that with reverse voltage applied even slightly below the zener voltage there will be some current flow. This can be a problem in some circuits if not understood and accounted for.
Is diode characteristic symmetrical?
Absolutely not. An ideal diode's characteristic would be perfect conduction in the forward direction and perfect insulation (no conduction) in the reverse direction. Silicon diodes come respectably close.
What does diode mean in a science?
A diode is an electronic component with the characteristic that its resistance is not constant, but depends on the magnitude of the current through it. An ideal diode has zero resistance to current in one direction, and infinite resistance to current in the reverse direction.
Voltage-current characteristics of ideal diode?
An ideal diode would match the purpose of a diode without any of the drawbacks. The purpose of a diode is to control current flow - The diode "turns on" for current flowing in one direction, and "turns off" if current wants to flow in the other direction. Ideally, there would be no voltage drop across this diode when allowing current flow, thus no power loss. When the diode is "turned off" by a negative voltage, idealy there would be no current flow (no matter how large the negative voltage).
How is zener diode different from a conventional diode or ideal diode?
zener diode :zener diode operates under reverse bias voltageideal diode :ideal diode operates under forward bias voltage
Can diode work as switch?
yes diode can be used as a switch as it conducts current in only one direction.it is a open switch when it reverse biased.and as aclosed switch when it is forward biased.but we consider diode as ideal .
List the two conditions under which a diode is operated?
A diode is a semiconductor material which has p region and n region. In order to "turn on" and conduct current in the forward direction, a diode requires a certain amount of positive voltage to be applied across it. An ideal diode conducts only when the diode is forward biased, and then the voltage drop across the diode (Vd) is zero. When the ideal diode is reverse biased, no current flows. The two conditions to operate a diode are: (a) Current flow is permitted; the diode is forward biased. (b) Current flow is prohibited; the diode is reversed biased. When the polarity of the battery is such that current is allowed to flow through the diode, the diode is said to be forward-biased.
What is zener dioide?
Zener diode can be defined as diode which allows current to flow in the forward direction in the same method as an ideal diode, but will also allow it to flow in reverse direction when the voltage is above definite value known as the breakdown voltage
What is an ideal diode?
A: That is no such a diode but if it exists it will have unlimited reverse voltage capability the forward voltage drop will be zero no matter of current flow and it will remain so regardless of temperature changes
Is zener diode an ideal current source?
A: An ideal current source can be defined as a short with immense current capabilities A zener has no such capabilities
Why there is no current in reverse bias condition?
Current flows in a reverse biased diode because diodes are not ideal. They do have leakage current and a breakdown voltage in reverse, just as they have a breakdown current in forward and a non-linear and non-parallel forward voltage to current curve. It is also possible that you are looking at a zener diode. A zener diode is specifically design to conduct at a certain voltage in reverse.
How real diode is different from ideal diode?
It depends how "ideal" your ideal diode is. The first approximation of an ideal diode is that it's a device that allows current to flow one way, and not the other way, while doing this with no losses. The second approximation of a diode implies the inherent 0.7V drop across the device, as well as one way current flow, but with no loss resistance. The third approximation of an ideal diode is a device which allows current to only flow one way through it, with a 0.7V loss across is, as well as a small internal resistance of a few ohms. These all vary from a real diode because these are all linear, in every sense. You can neither calculate the voltage nor the current across/through a diode. Instead, you must use the diode's characteristic curve (given on datasheet), and linearize it. You can get any amount of current to flow through the diode the CORRECT direction, by changing the voltage used. A number of microamps will take perhaps, a third of a Volt.
What are characteristics of an ideal diode?
An ideal diode:Passes current in one direction only. (Under forward bias).Has no leakage current (passes no current under reverse bias).Has no forward voltage drop. (No voltage loss under forward bias - a real diode has Vd~=0.7)See links for more details.
How the diode acts as a switch?
A diode is made up of a P-Type and an N-Type semiconductor. P-Type has "missing" electrons (in a sense); N-Type has extra electrons (in a sense). This means that if you have current going through the two semiconductors from N-type into P-type, it should be easier than normal to apply the current because there is a potential difference between the N-type and P-type because of their relative "positivity" and "negativity". ...but if you reverse the voltage, then you are going against this potential difference and hence the voltage is impeded, resulting in a 0 current (in theory). This will only happen until the reverse voltage exceeds a threshold ampage, at which point the current will shoot up (in reverse).
