Dielectric loss

The energy consumed by a capacitor under the action of an electric field is usually represented by the

 ratio of the loss power to the reactive power of the capacitor, that is, the tangent of the loss angle 

(in the equivalent circuit of a capacitor, the ratio of the series equivalent resistance ESR to the capacitance 

1/ω C is called Tan δ, where ESR is calculated at 120Hz. Obviously, Tan δ increases with the increase of 

measurement frequency and decreases with the decrease of measurement temperature). The larger the

 loss angle, the greater the loss of the capacitor, and capacitors with large loss angles are not suitable

 for working at high frequencies. The dissipation factor (DF) exists in all capacitors, and sometimes the 

DF value is represented by the loss angle tan δ. The lower this parameter, the better. But the parameter

 for aluminum electrolytic capacitors is relatively high. Whether the DF value is high or low is related to 

temperature, capacity, voltage, frequency, etc. for capacitors of the same brand and series; When the 

capacity is the same, the higher the withstand voltage, the lower the DF value. In addition, the higher 

the temperature, the higher the DF value, and the higher the frequency, the higher the DF value.

External dimensions

The external dimensions are related to weight and pin type. Single ended is radial lead type, screw is 

locking screw type, and there are also surface mount aluminum electrolytic capacitors. As for weight, 

two capacitors with the same capacity and withstand voltage, but different brands, must have different

 weights when compared; And the external dimensions are more related to the shell planning. Generally 

speaking, capacitors with the same diameter and capacity can be replaced with capacitors with higher

 heights for those with lower heights. However, when replacing capacitors with lower heights for those 

with higher lengths, the issue of mechanism interference must be considered.

ESR

A capacitor will generate various impedances and inductances due to its structure. ESR equivalent series 

resistance and ESL equivalent series inductance are important parameters - the basis of capacitive

 impedance. A capacitor with a small equivalent series resistance (ESR) and a relatively large external

capacitor can effectively absorb the peak (ripple) current during rapid conversion. It is more cost-effective 

to use capacitors with high ESR in parallel. However, this requires a compromise between PCB area, 

number of components, and cost.

Ripple current and ripple voltage

Also known as ripple current and ripple voltage, it is actually ripple current, ripple voltage。 The meaning 

is that capacitors can withstand ripple current/voltage values. Ripple voltage is equal to the product of

 ripple current and ESR.

When the ripple current increases, even with the ESR remaining constant, the ripple voltage will increase 

exponentially. In other words, as the ripple voltage increases, the ripple current also increases, which is

 why capacitors are required to have lower ESR values. After adding ripple current, the equivalent series

 resistance (ESR) inside the capacitor causes heating, which affects the service life of the capacitor. Generally, 

ripple current is proportional to frequency, so ripple current is also relatively low at low frequencies. The

 rated ripple current is a numerical value defined under the highest operating temperature conditions.

 In practical applications, the ripple tolerance of capacitors is also related to their operating environment 

temperature and the temperature level of the capacitor itself. Specifications usually provide a maximum 

ripple current that capacitors of each temperature level can withstand under specific temperature conditions. 

Even provide a detailed chart to help users quickly find the capacitance ripple allowed to achieve a certain 

expected service life under certain environmental temperature conditions.

Leakage current

The dielectric of capacitors has a significant hindering effect on direct current. However, due to the 

presence of electrolyte on the aluminum oxide film dielectric, a small current called leakage current is 

generated during the re formation and repair of the oxide film when voltage is applied. Usually, leakage

 current increases with temperature and voltage. Its calculation formula is roughly: I=K × CV. The unit of

 leakage current I is μ A, and K is a constant. Generally speaking, the higher the capacitance of a capacitor, 

the greater the leakage current. From the formula, it can be inferred that the higher the rated voltage, 

the greater the leakage current. Therefore, reducing the operating voltage can also reduce the leakage 

current.

life

Firstly, it should be clarified that aluminum electrolytic capacitors are bound to break down, it's just a 

matter of time. There are many reasons that affect the lifespan of capacitors, such as overvoltage, reverse 

voltage, high temperature, rapid charging and discharging, etc. Under normal use, the biggest impact is

 temperature, because the higher the temperature, the faster the evaporation loss of electrolyte. It 

should be noted that the temperature here does not refer to the environment or surface temperature, 

but to the working temperature of the aluminum foil. Manufacturers usually label the lifespan and testing 

temperature of capacitors on the capacitor body. As the working temperature of capacitors increases by

 10 ℃, their lifespan is halved. Therefore, do not assume that aluminum electrolytic capacitors with a 

lifespan of 2000 hours are better than those with a lifespan of 1000 hours. Pay attention to the testing 

temperature for confirming the lifespan. Every manufacturer has calculation formulas for temperature 

and lifespan, and when designing capacitors, actual data should be referenced for calculation. It should

 be understood that in order to improve the lifespan of aluminum electrolytic capacitors, firstly, the 

operating temperature should be lowered and the PCB should be kept away from heat sources. Secondly, 

capacitors with the highest operating temperature should be considered, although the price may also 

be higher

impedance

The resistance that obstructs the passage of alternating current at a specific frequency is called impedance. 

It is closely related to the capacitance and inductance values in the equivalent circuit of capacitors, and

 is also related to ESR. The capacitance reactance of a capacitor gradually decreases with increasing 

frequency in the low frequency range, and when the frequency continues to increase and reaches the 

mid frequency range, the reactance drops to the value of ESR. When the frequency reaches the high

 frequency range, the inductive impedance becomes dominant, so the impedance increases with the

 increase of frequency. The output filtering electrolytic capacitor in a switching power supply has a sawtooth

 voltage frequency of up to tens of kHz, even tens of MHz. At this time, capacitance is not its main

 indicator. The standard for measuring the quality of high-frequency aluminum electrolytic capacitors

 is the "impedance frequency" characteristic, which requires a low equivalent impedance within the 

operating frequency of the switching power supply and good filtering effect on high-frequency peak 

signals generated by semiconductor devices during operation.

About Us

Guangdong Fulong Electronic Technology Co., Ltd. is a private high-tech enterprise specializing in the research and development, manufacturing, and sales of aluminum electrolytic capacitors, certified by IATF16949，ISO9001, ISO14001, and ISO45001. The company has a building area of 17000 square meters and more than 50 automated production lines; The total investment is 50 million yuan (RMB), with more than 100 employees, including more than 20 engineering and technical, quality management, and production management personnel. The annual production of capacitors (4 * 5.4~16 * 21.5) is about 400 million pieces; Our products are mainly sold to domestic and international markets, and we strive to promote our company's products globally.

Jiangxi Fulong Electronic Technology Co., Ltd. is a wholly-owned subsidiary of Guangdong Fulong Electronic Technology Co., Ltd. established in Hukou County, Jiangxi Province with a total investment of 500 million yuan. It has 50 fully automated production lines and an annual output of approximately 1.2 billion capacitors (4 * 5.4~16 * 21.5).

Fulong Group has an international professional core technology research and development team for aluminum electrolytic capacitors and a global sales network. Rich experience in the design, research and development, and production management of aluminum electrolytic capacitors. The R&D team follows the technical design theory of aluminum electrolytic capacitors, complies with international and domestic legal and regulatory requirements (RoHs), and adheres to the highest international quality standards

Fulong Group has high-quality and stable raw material supply partners, and key raw materials (such as aluminum foil, electrolytic paper, etc.) are selected from well-known Japanese and Korean companies (KJCC KDKNKK, etc.), ensuring reliable and stable advantages in product quality, environmental protection, safety, and energy conservation.

Fulong Group has a group of highly qualified professional technicians and management personnel who can produce various series of sheet aluminum electrolysis products according to customer requirements. The products include high-frequency low impedance, low leakage, wide temperature, extremely low impedance, non-polar, ultra long life, medium high voltage long life, high reliability and other new types of special requirements for surface mount products; At the same time, the company's products can withstand a soldering temperature of 260 ℃, meeting the lead-free reflow soldering technology required for SMT in the whole machine factory. All technical indicators of the products have reached or exceeded the international level of similar products.

While strengthening management and expanding operational scale, Fulong Group is also committed to improving its competitiveness and customer satisfaction, continuously and steadily increasing customer and social trust, continuously meeting market demand, further optimizing environmental management and expanding social contributions, and developing together with the electronics industry.

Guangdong Follon Electronic Technology Co., Ltd.

Jiangxi Follon Electronic Technology Co., Ltd.

Address: Building 3, South District, Haishan Science and Technology Park, Hukou County, Jiujiang City, Jiangxi Province

www.follon.com

Professional manufacturer of high-quality surface mount electrolytic capacitors