Tantalum Capacitors VS Ceramic Capacitors

The function of capacitors is to remove the crosstalk of various high-frequency signals generated by the chip itself to other chips so that each chip module can work normally without interference. In the high frequency electronic oscillating circuit, the SMT capacitance and crystal oscillator together form an oscillating circuit to provide the required clock frequency. Its main chemical components are nickel and chromium, and the shape is filamentous, so it is called nickel-chromium wire.

tantalum capacitors

Ceramic capacitors

Ceramic capacitors are made by high dielectric constant capacitor ceramics, which are extruded into tubes, wafers, or disks as the medium. It is divided into two types: high-frequency porcelain medium and low-frequency porcelain medium. Low-frequency ceramic dielectric vessels are limited to those occasions where they are used as by-passes or dc insulation in circuits with lower operating frequencies, or where stability and loss requirements are not high. Such capacitors are not suitable for use in pulse circuits because they are vulnerable to breakdown by impulse voltage.

Ceramic Capacitors

Tantalum Capacitors

Tantalum capacitors are characterized by long life, high-temperature resistance, high accuracy and excellent performance of the high-frequency filter. Tantalum capacitors can generally withstand high temperature and voltage and are often used for high-frequency filtering. Ceramic capacitors look a bit like patch resistors, but they are smaller in capacity and more expensive than aluminum capacitors and have relatively low voltage and current resistance.

Compared with ceramic capacitors, tantalum capacitors on SMT are labeled with capacitance and pressure resistance, and the surface color is usually yellow and black. SMT aluminum electrolytic capacitors have a larger capacity than SMT tantalum capacitors, which is more commonly seen on the display card, with a capacity between 300 VPS F and 1,500 VPS F.

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Tantalum Capacitors

The difference between tantalum capacitors and ceramic capacitors

They are made of different materials. As the name implies, tantalum capacitors use tantalum as the medium, while ceramic capacitors use ceramics as the medium. The capacitance of ceramic capacitors is much smaller than that of tantalum capacitors. Tantalum electrolytic capacitors can achieve a small capacitance, while the ceramic capacitor can hardly achieve the ideal performance when the capacitance is large.

Tantalum capacitors and ceramic capacitors also have different uses. Tantalum capacitors can be used as coupling, and the frequency range of such circuits as filter oscillatory bypass is large, while ceramic capacitors are mostly used in high-frequency circuits. Since tantalum capacitors are mainly made of tantalum, a very rare metal, so the capacitor grade tantalum powder is very expensive, while tantalum capacitors are sold at a high price and generally used only in high-end products that are not price-sensitive.

Multilayer ceramic capacitors are now the most widely used in almost all electronic products. In recent years, the capacity of ceramic capacitors has become larger and larger with the continuous progress of technology, and 47UF multi-layer ceramic capacitors have emerged. However, the large-capacity ceramic capacitors can only be made by a few big Japanese brands, so the price is still more expensive, which is similar to the price of tantalum capacitors.

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How to Select a Tantalum Capacitor?

What is a tantalum capacitor?

At present, the tantalum capacitor is still a kind of charge energy storage device with a small volume but high capacity, and the amount of electric energy it can store depends on the thickness and area of the medium.

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The dielectric capacity of the tantalum capacitor’s dielectric layer can reach 120KV/mm, and its relative dielectric constant is 27 times 10-12 farad/meter. Therefore, tantalum capacitors can withstand extremely high field strength in a very thin medium layer, which is the root cause of their small size but high capacity. Tantalum capacitors are not only used in military communications, aerospace, and other fields, but also in industrial control, video equipment, communication instruments, electric vehicles, and other products.

Tantalum capacitors are mainly used for filtering, energy storage, and conversion, marking bypass, coupling, and decoupling and acting as the time constant elements. Pay attention to its performance characteristics in the application, and the correct use will help to give full play to its functions.

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How to select appropriate tantalum capacitors?

To choose tantalum capacitors, the first problem is to choose encapsulation, voltage resistance, and capacitance. The capacity determines the size (encapsulation) of tantalum capacitors; on the contrary, what size determines what capacity and pressure tolerance can be achieved. According to the market, the most common problem is that engineers ignore this problem in the design process, and always want to achieve the desired parameters on the smallest device.

For example, the capacity of type A 10UF can be seen to have a withstand voltage of 4v6.3v10v20v, however, if you want to use 25V10UF, only the B type of tantalum capacitor can be used. In addition, since tantalum capacitors are used for derating, generally 70% of the capacitors need to be used, that is, the working voltage is 10V, which should be divided by 0.7. The capacitors can only be used with 16V withstand voltage.

How to purchase the original tantalum capacitors?

Due to the wide variety of electronic components and special uses, the current component market is full of fake products, dismantling and refurbishing products. The choice of a high-quality, long-term cooperation of the business is particularly important.

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Currently, the world mainly has the following five brands of tantalum capacitors: AVX, KEMET, VISHAY, NEC, and NICHICON. Tantalum capacitors on the market are divided into two types: yellow tantalum and black tantalum. In simple terms, the black tantalum is produced by molding tantalum powder into shape, while the yellow tantalum is formed on the surface with polyoxide resin. Due to the production process, the internal space of black tantalum is not utilized most effectively, so the capacity of yellow tantalum is larger than that of black tantalum.

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