What is a chip diode? What products are SMD diodes used in?

SMD diode is a diode that is soldered through the SMT process, mainly used in consumer or ordinary electronic products, classification: 1According to the semiconductor data used, it can be divided into germanium diodes (GE tubes) and silicon diodes (Si tubes).

2.According to the die planning, it can be divided into point contact diodes, surface contact diodes and planar diodes.

3.According to its different uses, it can be divided into detection diodes, rectifier diodes, voltage regulator diodes, switching diodes, barrier diodes, Schottky diodes, light-emitting diodes, silicon power switching diodes, rotary diodes, etc.

Applications: A device with two electrodes in electronic components that allows only a single direction of current flow. Many of the uses are to apply their rectification features. Varactor diodes (VAFIC diodes) are used as electronic tunable capacitors.

A chip diode is a form of package, i.e., a diode without pins.

First of all, we need to figure out what is a patch?

SMD refers to the "mounting" of electronic components on the basis of a PCB.

There are many forms of packaging for electronic components, and chip packaging is one of them. Almost all electronic components are available in chip packages. Almost all home appliances, consumer electronics, medical electronics, industrial electronics, military electronics, etc. use SMD components.

Your phone's SMD electronics account for 99%.

SMD diodes.

It is to directly solder the diodes on the circuit board, and the volume cost is smaller than that of ordinary ones, and there are small and medium-power diode models on the patch.

Are you sure it's E1J? It should be es1j, right? Take a closer look to see if you're mistaken.

It can be replaced with a plug-in transistor.

The SMD triode and the plug-in transistor are the same, but the package is different. The patch is smaller, saving space and eliminating manual insertion. Plug-ins are generally in TO-92 packages, while SMDs are generally in SOT-23 packages. The amplification parameters are basically the same.

An important parameter of the transistor is the current amplification factor. When a tiny current is added to the base of the triode, a current that is times the injection current can be obtained on the collector, that is, the collector current.

And a small change in the base current can cause a large change in the collector current, which is the amplification effect of the SMD triode. The transistor can also be used as an electronic switch, and can be used to form an oscillator with other electronic components.

First, the role is different.

1. SMD regulator: voltage regulator or voltage reference element.

2. SMD diode: many of the uses are to apply their rectification function.

Second, the characteristics are different.

1. SMD regulator: In the reverse breakdown, the terminal voltage is almost unchanged within a certain current range (or within a certain power loss range), showing voltage stabilization characteristics.

2. SMD diode: This electronic device has the conductivity of unidirectional current according to the direction of the applied voltage.

Third, the principle characteristics are different.

1. SMD regulator tube: It works by using the breakdown zone of the PN junction with the characteristics of stable voltage.

2. SMD diode: When the applied voltage is equal to zero, the diffusion current caused by the concentration difference between the carriers on both sides of the P-N junction and the drift current caused by the self-built electric field are equal and are in an electrically balanced state.

Connect a large resistor in series into the circuit to measure the voltage at both ends of the voltage or the power supply voltage, indicating that it is a diode.

Conversely, the regulator tube.

A chip regulator is one of the chip diodes.

SMD diodes, glass shell encapsulation, resin coating, and molded plastic packaging, the most common are divided into switching, voltage regulation, rectification, fast recovery, Schottky, triggering, and capulescence change, which are more common, and can be divided into cylindrical and sheet according to the appearance shape.

The regulator can be packaged in any of the above diode methods.

There is a word on the regulator tube, and then it is a data sheet.

If there is no word, string the resistor and the regulator tube together, and then use a power supply that is greater than the voltage of the regulator tube. It is sufficient to measure the voltage of the regulator tube directly.

For example, if it is estimated that the voltage of the regulator tube is about 5V, then you can use a 12V power supply and a 1K resistor for experiments. If 12V is measured, the estimate is wrong and a higher voltage and greater resistance should be used. If it is measured, then it is a regulator tube.

This is the SMD diode, which is flat on the PCB when soldered.

For SMD components, reflow soldering is mostly used in the industry. (suitable for mass production).

For sporadic soldering, you can also use a soldering iron. For example, during maintenance work.

A type of diode, which belongs to the kind of miniature

It's the kind of square sheet that sticks to the circuit board.

1. The packaging of the LED is transparent, and the shape of the contact electrode inside can be seen through the shell, the positive electrode is a large square, and the negative electrode is a small dot.

2. The digital multimeter has the item that the measuring point path is on/off, and the icon is a diode and a small speaker. When the red wire of the multimeter is connected to the positive end of the LED and the black wire is connected to the negative end of the LED, the LED will be lit.

3. Judging from the mark drawn on the silk screen layer, it should be positive on the left and negative on the right. Use a digital multimeter, put it in the diode file, use the probe to touch both ends of the LED, and when it is shining, the red watch pen will contact the + of the LED.

1.Observe. The shape of the two lead wires in the tube is observed from the side, and the smaller one is the positive electrode.

2.Look at the length of the pins, the positive and negative poles of the SMD light-emitting diode, the long pins are positive, and the short ones are negative.

3.The most intuitive way to look at the real thing, the SMD light-emitting diode is divided into positive and negative poles, one end of which has an extra pin, carefully observe the pin side of a small hole, this small hole is convenient for us to distinguish the important components of the positive and negative poles of the SMD light-emitting diode, the end with a small hole is the positive pole, but this small hole pin has no practical effect, when welding, you still need to weld the two pins like small pins, the pins of the large connection of the bracket are the negative pole, and the pin of the small link of the bracket is the positive pole.

Generally speaking, there will be marks on the surface of the diode's package, some are a line, and some are a triangle.

SMD diodes generally have a horizontal line at one end, and the one with a horizontal line is the negative pole.

1. The notched end is the negative electrode.

2. The end of the horizontal bar is the negative pole.

3. One end of the white parallel bar is the negative pole.

4. One end with a triangular arrow is the negative pole.

5. One end with a colored line is the negative electrode.

As with ordinary diodes, the one with more color area is positive.

Measured with a multimeter, the resistance value is small and the one is positive.