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Point 1. What is the impedance difference between MnZn ferrite and NiZn ferrite common mode inductors at 30MHz frequency?
Answer: The permeability of MnZn ferrite can reach 5,000,
  but permeability may start to decline at 20kHz frequency. At 30MHz frequency, its permeability has decreased significantly, resulting in relatively low impedance.
  NiZn ferrite has low initial permeability but maintains permeability unchanged at high frequencies (100MHz). At 30MHz, it can maintain certain permeability, so impedance is relatively high. However, specific...

Question 1. How to calculate the saturation margin of common mode inductors based on the circuit's maximum surge current?
Answer: The saturation margin of common mode inductors is a key parameter to ensure they do not enter magnetic saturation under surge current. Calculation steps are as follows:
 
Key logic: Differential mode currents generate magnetic fluxes that cancel each other in common mode inductors, usually not causing saturation; while common mode surge currents superimpose magnetic flux, potentially saturating the core. Margin needs to be achieved through core material selection and increasing coil turns or magnetic circuit cross-sectional area.
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Question 2. What is the...

The self-resonant frequency (SRF) of a common mode inductor is determined by its inductance and parasitic capacitance. When noise frequency approaches SRF, impedance reaches peak, and filtering effect is optimal; beyond SRF, parasitic capacitance dominates, impedance decreases, and filtering performance deteriorates. Design must ensure SRF is higher than target noise frequency band.

What are the Three Main Categories of EMI Inductor Core Materials?
First Category: Ferrite Cores
Mn-Zn ferrite, Ni-Zn ferrite
Second Category: Metal Powder Cores
Iron Silicon Aluminum (Sendust), Iron Nickel Molybdenum (MPP), Iron Silicon (Fe-Si), Carbonyl Iron Powder Core (Carbonyl Iron)
Third Category: Nanocrystalline Alloys
Iron-based nanocrystalline alloy, iron-based amorphous
 
What are the Ten Evaluation Indicators for Magnetic Materials?
1. Permeability (μ)
Definition...

Open Alliance Test refers to a series of tests conducted by the OPEN Alliance for automotive Ethernet-related devices and systems, aimed at ensuring compatibility and interoperability between vehicle internal network components. Details are as follows:
OPEN Alliance
OPEN Alliance SIG is a non-profit open industry alliance jointly established by OEMs, tier1, and tier2, mainly consisting of over 160 automotive OEMs and suppliers worldwide, dedicated to promoting and applying Ethernet technology in automotive environments.

Overview of Common Communication Protocol Common Mode Inductors and Electrostatic Protection Devices




Protocol
Protocol


Speed/rate
Speed


ESD S/N
ESD Protection Model

Packing Size
Package
CML S/N Common Mode Inductor Model
Packing Size Package
GMSL
12Gbps

01 Basic Knowledge and Importance of Inductors
Inductors are components that can convert electrical energy into magnetic energy and store it. Their structure is similar to transformers but with only one winding. They have certain inductance, characterized by passing direct current and impeding alternating current. When current flows through a conductor, an electromagnetic field is generated. Inductance is a physical quantity that measures the ability of a coil to generate electromagnetic induction; when current is applied to a coil, a magnetic field is generated around the coil, with magnetic flux passing through. The larger the applied current, the stronger the magnetic field and the greater the magnetic flux. The ratio of magnetic flux through the coil to the applied current is proportional, and their ratio is called the self-inductance coefficient, which is inductance.
The role of inductors...

1. Why Do We Need Common Mode Inductors?
1.1 CAN bus interference mainly comes from common mode noise and differential mode noise. Common mode noise commonly includes ground loop interference and EMI (electromagnetic interference), which is generated simultaneously in both transmission lines, with potential referenced to ground.
For example: In complex electromagnetic environments, electromagnetic interference generated by nearby large electrical equipment during operation may enter the CAN bus through space coupling, forming common mode noise ; Differential mode noise is mainly signal crosstalk, generated between two transmission lines. For instance, during high-speed data transmission, signals from adjacent signal lines may interfere with each other, causing...

1 Background of New Energy Vehicle Communication Networks
With the rapid development of new energy vehicles, the intelligence and automation level of vehicles continues to improve, making communication between electronic control units (ECUs) within vehicles increasingly critical. The communication network is like the "nervous system" of new energy vehicles, responsible for transmitting various control instructions and data information, ensuring coordinated operation of various vehicle systems.

In new energy vehicles, the battery management system (BMS) needs to communicate in real time with the motor controller (MCU), vehicle controller (VCU), etc., to achieve precise...