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What are Cathode and Anode?

What are Cathode and Anode?

Let us understand what cathode and anode exactly mean. They are both defined by the flow of current. Therefore, a cathode is an electrode from which the current exits a polarized electrical device.
Likewise, an anode is an electrode from which a current enters into a polarized electrical device.

The terms were finalized in 1834 by William Whewell who adapted the words from the Greek word (kathodos), ‘descent’ or ‘way down’. William had consulted with Michael Faraday for the coining of the terms.


When we talk about cathode in chemistry, it is said to be the electrode where reduction occurs. This is common in an electrochemical cell. Here, the cathode is negative as the electrical energy that is supplied to the cell results in the decomposition of chemical compounds. However, it can also be positive as in the case of a galvanic cell where a chemical reaction leads to the generation of electrical energy.

In addition, a cathode is said to be either a hot cathode or a cold cathode. A cathode which is heated in the presence of a filament to emit electrons by thermionic emission is known as a hot cathode whereas cold cathodes are not heated by any filament. A cathode is usually flagged as “cold” if it emits more electrons compared to the ones generated by thermionic emission alone.


In the most basic form, an anode in electrochemistry is the point where an oxidation reaction occurs. Generally, at an anode, negative ions or anions due to its electrical potential tend to react and give off electrons. These electrons then move up and into the driving circuit.

If we take a galvanic cell, the anode is negative in nature and the electrons mostly move towards the external part of the circuit. In an electrolytic cell, it is again positive. Additionally, an anode can be a plate or wire having an excess positive charge.

Difference Between Anode And Cathode

Here are some key differences between cathode and anode.



The   anode is the electrode where electricity moves into.

The   cathode is the electrode where electricity is given out or flows out.

The   anode is usually the positive side.

A   cathode is a negative side.

It   acts as an electron donor.

It   acts as an electron acceptor.

In   an electrolytic cell, oxidation reaction takes place at the anode.

In   an electrolytic cell, a reduction reaction takes place at the   cathode.

In   galvanic cells, an anode can become a cathode.

In   galvanic cells, a cathode can become an anode.

Why do YOU need to Second Source a component?

This was a question many people asked years ago before this market change. “Why do I need to second source if my supply chain is fine?”
Now, we are getting the question “Can you find me a second source?”

Shortage bothers everyone in electronic components field over year and it’s continue. Especially the shortages for IC, MCU, MOSFET etc. 
Lead time is being pushed out to 90+ weeks for some parts and prices are being raised sometimes more than several times.
Given above, it’s necessary for you to consider a few new Chinese supplier like Topdiode in order to secure and improve your supply chain.

How can Topdiode help?  

Topdiode Group (Topdiode & UF Capacitor) is a leading manufacturer of wide range components, covering capacitors, diode & transistors and MOSFET in China Since 1995.
As a Chinese factory, we are not only good at fast lead time but also quality control. Our market position is to replace first tier brands like Murata, TDK, AVX, Vishay, Littelfuse, Onsemi, Diodes etc with similar quality but much better price.  We keep stock for chip MLCC and some fast running tantalum capacitors, for balance, lead time is around 4 weeks.

Come to contact us for solutions to shortage and cost down, grow business together.

The difference between Safety capacitors Class X & Class Y

Since capacitors in EMI filters are connected to ac power lines, these capacitors can fail due to over-voltages and transients. They are classified according to their use in the circuit. Capacitors connected line-to-line are called “X capacitors,” also called “line to neutral” capacitors. Those connected from line-to-ground are called “Y capacitors,” also referred to as “line bypass capacitors.”

X capacitors are used for differential-mode EMI filtering. Y capacitors are used for common mode EMI filtering bypassing the interference from the wires to ground. Since safety capacitors are directly connected to the mains voltage, they can be subjected to voltage transients, power surges, overvoltage conditions, and other stresses resulting in device failure. They are designed for specific failure modes. Failure of X capacitors could result in a fire. X capacitors are designed to fail shorted, which causes a fuse or circuit breaker connected to the device to open, preventing the possibility of a fire.

The shorting of a Y capacitor could present a fatal shock hazard for personnel using the equipment. As a result, Y capacitors are designed to fail open and prevent any possibility of a shock hazard. While the equipment is shut down by failure of an X capacitor and the subsequent tripping of an overcurrent protection device when a Y capacitor fails, the equipment could continue operating, but EMI filtering would be significantly reduced.

Safety capacitor standards
Because a shorted Y capacitor could lead to the danger of an electric shock, Y capacitors are held to a higher operating standard compared with X capacitors. During the certification process, two key tests performed are the impulse and endurance tests. These are done to verify that the X/Y capacitor can withstand ten impulses of alternating polarity, followed by a 1000-hour endurance AC life test. After completing these two tests, the capacitors must still perform reliably in the circuit under AC voltage conditions. These tests are part of the IEC 384-14 certification requirements.

A design consideration when using X capacitors is the need to automatically discharge the capacitor upon loss of power to the power converter to comply with safety standards. Several suppliers offer integrated circuits that can be placed in series with bleed resistors (also called discharge resistors) that automatically discharge the energy in the X capacitor when the mains voltage is disconnected, diverting the energy away from the exposed AC plug and protecting equipment users.

#UF_capacitors is a professional ISO9001 factory in safety capacitors disc_capacitors #Y1 #Y2 #X2 for more than 27+ years, meeting international safety standards such #ENEC, #UL, #CQC, #KC/KTL an #VDE. #UL recognized lab test in factory & could issue UL test report directly. Compared to #Kemet, #Murata, #AVX #Vishay etc L/T more than 20~40+ weeks, we could manage #fast_ lead_time around 4 weeks at competitive.

Russia restricts rare gas exports, which may exacerbate global chip supply constraints

Russia has restricted exports of noble gas, including neon and helium, based on approved government decrees.

These gases are indispensable raw materials for the production of semiconductors.

Russia supplies up to 30% of the world's inert gases. The government document said that exports of noble gas can now only be carried out on the basis 

of the government's decision on the advice of the Ministry of Industry and Trade. This could adversely affect global chip supply.

Vasily Shpak, Deputy Minister of Industry and Trade of Russia, said on Thursday (June 2) that the policy of restricting the export of rare gases will continue 

until the end of 2022 to strengthen its position in the international market.

Helium and neon are both important components needed to make chips. Neon, in particular, plays a key role in the manufacturing of advanced semiconductors.

Ukraine, once one of the world's largest suppliers of the noble gas, produced about half of the world's neon gas before factories in Mariupol and Odesa 

were shut down by the fighting in March.

Spark told Reuters that Russia's move would provide an opportunity to "rearrange those chains that are now broken and build new ones".

The Russian government has said on May 30 that until December 31, the export of noble gases that Russia used to offer to Japan and other countries will 

only be carried out with special permission from the state.

Russia currently accounts for 30 percent of the global supply of rare gases, according to estimates by the Russian Trade Ministry.

 India's "Economic Times" (The Economic Times) said that according to a resolution of the Russian cabinet of ministers, now only the Russian government 

can decide whether these rare gases can be delivered to the outside world.

Sources told the outlet that it would be more difficult for some countries to produce electronics without Russia's neon, argon and helium.

Russia's export restrictions could exacerbate supply constraints in the global chip market. The move could allow Russia to export these gases in exchange for semiconductor imports.

Taiwan, the world's main chip-producing region, imposed restrictions on chip exports to Russia after the war between Russia & Ukraine on February 24.

The Russian Ministry of Industry and Trade has confirmed that the agreements already reached will be taken into account when making decisions on the 

export supply of these gases.

The difference between #BJT(bipolar junction transistor) vs #MOSFETs

#BJT (BIPOLAR JUNCTION TRANSISTOR) and #MOSFET are two types of #semiconductor #transistors.

Even though both of them are transistors, they are different from each other in various aspects as following

Topdiode is an ISO9001 manufacturer in transistor and #MOSFET(small SMD) for more than 27+ year in China.

We offer equivalent to replace #Diodes #Diotec #Littelfuse #onsemi etc with #fast lead time, reasonable price.

Topdiode is one of the approved supplier to GE, Philips, Honeywell, Bosch's OEM fty in China. 

Lead time is short to 4-5 weeks for most items. Thanks.

What is the MSL (Moisture sensitivity level) of the multilayer ceramic capacitors?

What is the MSL (Moisture sensitivity level) of the multilayer ceramic capacitors?

The MSL level of multilayer ceramic capacitors was level 1 when evaluated by our company.

However, since products compatible to reflow soldering are applicable to MSL, products dedicated to flow soldering, such as parts with leads, are not applicable.

MSL is a JEDEC standard, and is intended for the phenomenon where the cubical expansion generated by the gasification of the moisture included in the product due to the moisture absorption of the product and the reflow soldering during mounting, which results in failures. The level that expresses this risk is the "MSL" (Moisture Sensitivity Level). As the level increases, the risk becomes higher; therefore, it is necessary to prevent moisture absorption when the level reaches 2 or more. For that reason, products of level 2 or higher must go through a baking process at a fixed period, and the tape reel is packaged in an aluminum pack with a desiccant.

UF capacitors is an 27+ ISO ISO9001:2015 mfg in China, sells to Honeywell, GE Philips and Huawai.

We keep semi-stock for chip MLCC. being dedicated to offer solution for shortage.

What is the Difference between #Active and #Passive Components

Active Components:

Those devices or components which produce energy in the form of Voltage or Current are called Active Components

Examples: DiodesTransistors SCR etc…

Passive Components:

Those devices or components which store or maintain Energy in the form of Voltage or Current are known as Passive Component

Examples:  Resistor, Capacitor, Inductor etc…

In very Simple words;

·        Active Components: Energy Donor

·        Passive Components: Energy Acceptor

#Topdiode & UF capacitors,  produces both #active and #passive #electronic #components in China.
Our market position is to replace world-class famous brands like #AVX, #TDK, #EPCOS, #Murata, #Littel_fuse etc with much better price, shorter L/T with reliable quality.
We keep stock for #MLCC, #tantalum_capacitors, fast L/T around 4-5 weeks for most of items.

Overlapping Applications of Capacitor Types

Overlapping Applications of Capacitor Types

UF capacitors L/T 4-5 weeks for most of parts.

#MLCC #tantalumcapacitors #ecap #AluminumCaps #polymer #filmcapacitor #MKP 
#Fast_delivery #electronic_component #cermeric_capacitor #radial

CA45 100uF 6.3V Case A CA45T107K0006000AR

Introduce you a GREAT part -- CA45 100uF 6.3V Case A  #CA45T107K0006000AR
Following up to #AVX, UF capacitors is the second Fty could produce it in China.
#Tantalum_capacitors #Case_A #China_supply #Component_supplier #Fast_delivery #PCBA

Happy Lantern Festival!

Give my best wishes to you: Reunion every year, peace and security every day!
From Topdiode group UF capacitor factory.