Mell What is knee current of a diode?
The knee voltage for a silicon diode is approximately 0.7 volt and for a germanium diode 0.3 volt. A semiconductor diode’s behavior in a circuit is given by its current–voltage characteristic, or I–V graph.
What do you mean by knee current?
The forward voltage at which the current through the junction starts increasing rapidly, is called the knee voltage or cut-in voltage. The reverse voltage at which P-N junction of a diode breaks down with sudden rise in reverse current is known as break down voltage.
What is meant by zener current?
A Zener diode is a silicon semiconductor device that permits current to flow in either a forward or reverse direction. The diode consists of a special, heavily doped p-n junction, designed to conduct in the reverse direction when a certain specified voltage is reached.
What is minimum zener current?
Current : The current, IZM, of a Zener diode is the maximum current that can flow through a Zener diode at its rated voltage, VZ. Typically there is also a minimum current required for the operation of the diode. As a rough rule of thumb, this can be around 5 to 10 mA for a typical leaded 400 mW device.
What does Zener knee and break down voltage mean?
This sharp change in zener current is called as knee or zener knee of the reverse characteristics. The reverse bias voltage at which the breakdown occurs is called zener breakdown voltage, denoted as V This value is carefully designed by controlling the doping level during manufacturing.
Is the Zener voltage lower than the reverse voltage?
However, a Zener may produce a voltage very close to the Zener voltage at current levels much lower than the reverse current and as low as the minimum Zener knee current, Izk.
When to use reverse leakage current in Zener?
Reverse leakage current is specified for a reverse voltage that is less than the knee voltage. This means that the Zener is not in reverse breakdown for these measurements. For example is for a reverse voltage of 1V in a 1N4728A.
Where does the current flow in a Zener diode?
In the forward bias of Zener diode, once the voltage at the anode terminal is superior to the knee voltage (threshold voltage) on the cathode, then it conducts current. The current flows from the anode to the cathode.