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How much forward diode voltage is there with the ideal diode approximation?
Wiki User
∙ 6y ago
Consider ideal diode to be connected in series with resistor of 6k
Silicon diode forward bias voltage = 0.7 volts
Current across 6k resistor = (5-0.7)/6000 amperes
Voltage across {resistor + diode}=4.3 + 0.7=5v
If silicon internal resistance is 6k then voltage across diode=5v
If external resistance is 6k and diode resistance is negligible then voltage across diode=0.7v
Wiki User
∙ 14y ago
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Which diode have characteristics very close to that of an ideal voltage source?
zener diode
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
What is the difference between ideal and practical pendulum?
An Ideal pendulum is ones that would be the first choice if you could choose all the materials (ideal materials). A practical pendulum is one that is readily available and reliable (made from things you have right now and are available to use).
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.
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 a conventional diode or ideal diode?
zener diode :zener diode operates under reverse bias voltageideal diode :ideal diode operates under forward bias voltage
What is the voltage drop of an ideal diode?
forward bias 0 volts, reverse bias infinity volts.
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.
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
Which diode have characteristics very close to that of an ideal voltage source?
zener diode
What are the various uses of diode?
Most people think of diode as a rectifier. Fair enough, it is because an ideal diode is taught to be a rectifier. In fact most people like the ideal diode characteristic; but dislike the non-ideal characteristics of diodes. However, some of the important inventions of our time are based on non-ideal characteristics of the diode. Below are a couple of samples: 1) Temperature sensor. A diode voltage changes with temperature. Assuming a fixed current going through the diode in the forward biased region, and the current is low enough that the diode resistance does not affect the voltage, the forward voltage has a negative temperature coefficient of about -2mv/degreeC. Once the temperature and voltage relationship is characterized with a fixed current, one can tell easily the temperature from the reading of the forward voltage. 2) Bandgap reference and regulator. This is related to temperature sensing as well. Since diode voltage has a negative temperature coefficient, a positive temperature coefficient voltage component added to the diode forward voltage would make an excellent stable voltage reference; a voltage that is independent of temperature. Turns out, the forward voltage is not only a function of temperature, it is also a function of current. To make life more interesting, the temperature coefficient of the voltage voltage is a function of current. In other words, if you have 2 identical diodes with different current through them, the difference in these two forward voltages also changes with temperature. this voltage is: Vd1-Vd2 = (k*T/q) *ln( I1/I2) where I1 and I2 are currents through the 2 identical diodes. This voltage has a positive temperature coefficient and is directly propositional to T in degrees Kelvin. Utilizing this current, one can amplify and convert it into a voltage, adding this voltage to a diode voltage, you have the making of a bandgap reference. As it turns out, this current is also great for temperature sensor applications.
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).
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
What is the difference between ideal and practical pendulum?
An Ideal pendulum is ones that would be the first choice if you could choose all the materials (ideal materials). A practical pendulum is one that is readily available and reliable (made from things you have right now and are available to use).
Which diode has its characteristics very close to that of an ideal voltagesource.1.zener diode 2.vacuum tube diode 3. crystal diode?
The Zener diode has the characteristics of a constant voltage source.
