Identification of Common Inductive Components

Identification of Common Inductive Components

SMD Wound Inductance

It is to surround many wires around the magnetic core and lead out the pad with pins. Due to the complexity of the process, the minimum inductance of the commonly used patch wound wire is the 0402 package. Small size wound inductors are usually used in RF circuits, combined with capacitors to form filters or matching networks.

In order to facilitate SMT production when being sucked by the suction nozzle, the patch wound inductor needs to add a flat cover.

The patch inductor itself is non-polar, and its surface screen printing has two forms: digital screen printing and color point screen printing. Sizes are available in various sizes.

Digital screen printing:

From left to right, the first and second digits represent the effective number of inductance values, and the third digit represents the number of digits to be multiplied after the effective number (the same as the digital identification method of resistance). The default unit is microhenryμH when the inductance element value is screen printed as a digital symbol.

The inductance value marked 100 is 10*100=10 microhenries

If there is a decimal point in the inductance, it is represented by "R" and accounts for a significant number. For example, the inductance marked "4R7" is 4.7 μH.

Color dot screen printing:

The side with dense color points is facing to your left, and the two color points close to yourself represent the first and second significant digits of the component value from left to right, and the point away from yourself is the number of digits to be multiplied by after the significant digits.

The screen printing of inductance is "red, red and red". According to the number corresponding to the color code, we can read the inductance value as: 22*102=22X100 = 2200nH = 2.2 μH.

chip laminated inductor

Laminated inductance, is encapsulated in the ferrite inside the multilayer circuit, multilayer circuit composition coil. The laminated inductor is small in size, the smallest commonly used materials can be 0201 in size, and the price is cheap, suitable for small volume and low requirements of the scene.

The reason why the requirements are not high is mainly because the precision of laminated inductors is general, the Q value is low, and the passing current is not large. There is no problem in general clutter filtering and radio frequency matching.

The laminated inductor looks similar to the chip capacitor: the two ends are pads, the middle is a gray or white cuboid, and the coil cannot be seen. Because the size is very small, so the body does not do the sense of the value of the logo, generally from the tray can see the specifications.

Sense value: 1R0(1.0uH)/frequency

Size: 0603(1608)inch/mm

Deviation: M gear (20%)

In the actual test, we can distinguish between the two as follows: the measurement of the resistance profile of the patch capacitor with a multimeter is open circuit; the measurement of the resistance profile of the inductor with a multimeter is short circuit.

In addition, there are some other inductive components, such as: beads, common mode chokes and so on. Magnetic beads are mainly used to suppress electromagnetic interference, and are usually used on signal lines or power lines to absorb high-frequency noise and make the signal clearer. The common mode choke is mainly used to suppress common mode interference and is often used on the power line of the computer to reduce the impact of electromagnetic radiation on the computer.