Ceramic Diode With 3 Legs

This is a fairly common practice in the industry.

Ceramic diode with 3 legs.

Used in voltage protection circuits. Integrated circuits are put into protective packages to allow easy handling and assembly onto printed circuit boards and to protect the devices from damage. Zener operated in reverse biased to hold a constant voltage. I don t have a solid answer as to why they do this but will share a few possibilities for debate.

Small signal used for applications with a much smaller current but with much more accuracy. A light emitting diode or led is a special type of diode that emits light when current passes through it. Transistors a transistor is a three terminal device in which a voltage applied to one of the terminals called the base can control current that flows across the other two terminals called the collector and the emitter. A wide variety of 3 legs led diodes options are available to you such as other.

Some of the special diodes arezener diode schottky diode varactor diode tunnel diode gunn diode light emitting diode led etc. Apart from schottky diode rest of the diodes are made by forming p type semiconductor to n type semiconductor. Look for legs on the side. Led stands for light emitting diode which means that much like their diode cousins they re polarized there are a handful of identifiers for finding the positive and negative pins on an led.

For a 1n4728a zener diode the value of v z is 3 3v and p z is 500mw as mentioned in specifications above now with supply voltage vs of 12v the value of rs will be. You can try to find the longer leg which should indicate the positive anode pin. When current is flowing through a diode the voltage on the positive leg is higher than on the negative leg this is called the diode s forward voltage drop. A very large number of different types of package exist.

Or if someone s trimmed the legs try finding the flat edge on the led s outer casing. In general single diodes in 3 lead sm packages have no connection on the third pin. A ceramic plaque with three bent legs and three wheat ears surrounding the head of medusa is widely known as the symbol of sicily. Rs 12 3 3 iz iz pz vz 500mw 3 3v 151ma therefore rs 12 3 3 151 0 0576 57 ohms rs 60ohms approx applications of diode.

The severity of the voltage drop is a function of the semiconductor material that the diode is made from. These are dialed to precise tolerances see the section on zener diodes in step 3. Some package types have standardized dimensions and tolerances and are registered with trade industry associations such as jedec and pro electron.