Contents
How is the threshold voltage of a diode determined?
The diode i-v characteristics can be plotted on a linear scale. Then one draw the best fitted straight line in the conduction region. The interception of the straight line with the voltage axes determines the the called cut in or the threshold voltage of the diode.
What is the maximum forward current a diode can conduct?
The maximum forward continuous current is the maximum continuous current the diode can conduct safely without damaging itself. If the diode is forced to conduct more than the maximum forward current, the heat generated at the P-N junction can permanently damage the diode. Peak forward current – I FSM or Non-repetitive Peak Forward Surge Current
What is the forward voltage of a germanium diode?
Forward voltage can be defined as the minimum voltage that when applied across diode triggers conduction in the diode. For silicon diodes, the typical forward voltage is around 0.7V and for germanium diode, the typical forward voltage is around 0.3V.
How is the threshold voltage and the cut in voltage related?
The cut in voltage = the threshold voltage, It is the not the cut off voltage. It is the voltage at which appreciable conduction starts. The onset of the conduction or the cut in voltage is an approximate boundary between the conduction off region and the conduction on region of the diode.
Due to the non-linear nature of the graph, the precise threshold voltage is sometimes found through a little geometry with the curve. Actually, it is a very simple and non-painful procedure. There is a straight part to the diode characteristic graph. All you have to do is to extend this part until it crosses the x-axis (Vf).
Is there a straight part to the diode characteristic graph?
There is a straight part to the diode characteristic graph. All you have to do is to extend this part until it crosses the x-axis (Vf). The point of intersection is the threshold voltage.
When does the forward voltage drop on a diode?
This value tells you that the diode will continue conducting even when the voltage falls as low as that figure. What most people do not realise is that the forward voltage drop is ideally specified when the forward current is zero. This is when the curve cuts the x-axis and the current is zero.
When does the diode become a fully conducting state?
As we increase the voltage further, to ~0.7 V, and ~0.8 V, the diode reaches a fully conducting state, and the current flow through it rises very fast. As you can see in the graph, the curve is almost vertical at around 0.8 V.