Analog Electronics

DIODE: Reverse Recovery Time

Now let’s analyze that what would happen when we change diode state from forward biase from reverse biase. This state change takes time which is known as reverse recovery time. Consider the following circuit of diode to analyze the switching time of diode. When the diode is in forward biase, the minority charge distribution of […]

Analog Electronics

Charge distribution of diode

Normal (un-biased) state: Apply the relation given below                                 n * p = ni2 at constant temperature    (Mass action law) Now we apply the above relation to p-type: p i.e. the concentration of majority carriers (holes) is larger as doping of p-side is high and we have the value of ni2as constant at fixed temperature. Hence from the […]

Analog Electronics

Switching time of Diode

The switching time of a diode is defined as the time which a diode takes to change its state from forward biased state to reverse biased state or in other words the forward current through diode doesn’t reduce to reverse saturation current immediately as the reverse voltage is applied. In fact it takes time for […]

Analog Electronics

Temperature effect on diode

The following graph shows the effect of temperature on the characteristics of diode A-B curve: This curve shows the characteristics of diode for different temperatures in the forward biase. As we can see from the figure given above, that curve moves towards left as we increase the temperature. We know with increase in temperature, conductivity […]

Analog Electronics

Breakdown of a diode

When the reverse voltage applied across diode becomes greater than the breakdown voltage, then the diode breaks down and very high current starts flowing in the circuit. There are generally two types of breakdowns in a diode: Zener breakdown Avalanche breakdown And based on the above classifications of breakdown of diode, we have the two […]

Analog Electronics

Diode: Reverse Biasing

 When the polarity of the external voltage source is opposite to the above case i.e. when positive terminal is connected to n-side and negative terminal to p-side, then diode is said to be reverse biased as shown below: When we reverse bias the diode, the majority carriers have again 3 types of forces acting on […]

Analog Electronics

Diode: Forward Biasing

When we apply voltage across the diode, as shown below: When the voltage applied across the diode is greater than the barrier voltage, the electrons and the holes present in the n-type and the p-type regions of the diode acquire enough energy to cross the barrier at the junction.                 Now if we talk in […]