This section provides an overview for common mode chokes as well as their applications and principles. Also, please take a look at the list of 7 common mode choke manufacturers and their company rankings.
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A common mode choke is a filter for reducing noise called common mode noise.
Common mode noise is a type of noise that travels over power and signal lines. The features of this noise are that it flows from the reference ground, through the wiring substrate, and back to the reference ground.
A common mode choke contains an inductor inside, which instantly interrupts the flow of noise when it flows.
A common mode choke plays an important role in noise suppression and EMC measures for electronic equipment.
Many electronic devices are subjected to EMC countermeasures so that they can operate normally even when affected by noise.
EMC stands for electromagnetic compatibility. This means that the product is designed not to give or receive electromagnetic interference, and even if it does receive electromagnetic interference, it is designed to operate normally.
Such EMC measures include electronic equipment, such as home appliances, office automation equipment, and vehicle machinery.
In particular, common-mode noise coils are used to eliminate common-mode noise, which is discussed below.
Conducted noise transmitted through power and signal lines is classified into two categories: differential mode noise and common mode noise.
First, in an electrical circuit built on a board, the current generated from one part of the circuit passes through the load and then returns through another route. This is called differential mode, and noise flowing in this way is called differential mode noise.
On the other hand, there is a route where the current does not loop through the circuit and because of the presence of capacitance between the reference earth and the wiring on the board, current flows between them and returns to the reference earth from the opposite side. This is called the common mode.
Normally, the capacitance between the reference earth and the substrate circuit is so small that low-frequency signals do not flow, but high-frequency noise can easily transmit common-mode noise due to the reduced impedance.
Common mode chokes are filters to eliminate common mode noise among these.
The coil has a structure of two conductors wound around a circular core.
When current flows in opposite directions in the two conductors (differential mode), the magnetic fluxes are in opposite directions and cancel each other out. Therefore, it does not function as a filter.
However, when currents flow in the same direction (common mode), the magnetic fluxes strengthen each other and act as an inductor, thus filtering noise.
*Including some distributors, etc.
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Laird Performance Materials, also known as Laird PM, specializes in heat and EMI protection for advanced electronics in automotive, aerospace and defense, telecommunications, data infrastructure, precision and computing, medical, and consumer electronics industries. As a global organization, Laird PM, focuses on developing, manufacturing, selling, and supplying precision-engineered materials used by manufacturers to serve their electronic markets. Laird PM designs and develops products test and measurement instrumentation to create models and product performance simulations to improve product performance, reliability, and flexibility while reducing development time and cost.
Ranking as of April 2023 GloballyDerivation Method
|1||Coilmaster Electronics Co., Ltd||22.2%|
|2||Laird Technologies, Inc.||22.2%|
|3||Renco Electronics Inc.||11.1%|
|7||Murata Manufacturing Co., Ltd.||11.1%|
Derivation MethodThe ranking is calculated based on the click share within the common mode choke page as of April 2023. Click share is defined as the total number of clicks for all companies during the period divided by the number of clicks for each company.
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