It undergoes electroluminescence process in which holes and electrons are recombined to produce energy in the form of light in forward bias condition. These diodes convert the electrical energy in to light energy. It is designed to prevent the other semiconductor devices from momentary voltage pulses. First produced by Clarence Zener in 1934, it is similar to normal diode in forward bias condition i.e., it allows current to flow.īut in reverse bias condition, the diode conducts only when the applied voltage reaches the breakdown voltage, known as Zener Breakdown. It is a passive element which works under the principle of ‘Zener Breakdown’. Since it has high current and voltage performance, these can be used in electrical devices which are used to suppress high peak voltages. In these diodes, the value of forward resistance is few Ohms and the value of reverse blocking resistance is in Mega Ohms. The main applications of these diodes are in Power Supplies (rectifiers, converter, inverters, battery charging devices, etc.). The large signal diodes are not suitable for high frequency applications. The large PN Junction also increases the forward current carrying capacity and reverse blocking voltage of the diode. Thus, they are usually used in rectification i.e., converting AC to DC. These diodes have large PN junction layer. Reverse Recovery Time – The time required for reverse current to fall down from forward current to I R.Maximum Forward Voltage at Peak Forward Current (V F at I F).Reverse Current (I R) – The current (very small value) that flows when it is reverse biased.Peak Reverse Voltage (V PR) – It is the maximum reverse voltage that can be applied to the diode before it breaks down.Some important characteristics of Small Signal Diode are: Small Signal Diodes are used in general purpose diode applications, high speed switching, parametric amplifiers and many other applications. The Small Signal Diode can be made of either Silicon or Germanium type semiconductor material, but the characteristics of the diode varies depending up on the doping material. Usually, these are in the range of 150mA and 500mW respectively. With respect to the other functionalities, the signal diodes usually have a small current carrying capability and power dissipation. For applications at high frequencies, the performance of the small signal diode is very effective. To indicate the cathode terminal, one edge is marked with black or red color. One of the popular diodes of this type is the 1N4148.Īppearance wise, signal diodes are very small when compared with power diodes. To protect the diode from contamination it is enveloped with a glass so it is also named as Glass Passivated Diode. It is a small device with disproportional characteristics whose applications are mainly involved at high frequency and very low current applications such as radios and televisions etc. Let us now briefly see about few common types of diodes.
There are many Different Types of diodes and some of them are listed below. Since diodes allow current to flow only in one direction and blocks current flow in the other direction, diodes are used in reverse polarity protector and transient protector applications. One of the main application of Diodes is Rectification i.e., to convert AC to DC. Usually, in Silicon Diodes, the dark band on one end of the diode indicates the Cathode terminal and the other terminal is anode.
For Silicon Diodes, the forward voltage is 0.7V and for Germanium diodes, it is 0.3V.
0 kommentar(er)
