- Catalogs
- Murata Electronics
- EMI Suppression Filters Application Guide
EMI Suppression Filters Application Guide
EMI Suppression Filters Application Guide
This document provides a comprehensive guide on noise suppression in electronic equipment using EMI suppression filters, specifically EMIFIL® and EMIGUARD® by Murata Manufacturing Co., Ltd. It focuses on understanding various EMI filters and their characteristics to effectively suppress noise in electronic circuits, particularly in DC circuits.
The document emphasizes the importance of reading ratings and cautions related to storage, operation, soldering, and handling to prevent hazards like smoking or burning. It advises obtaining product specifications approval before ordering.
- Desktop PCs: Solutions include improving shielding, installing EMI filters on interface cable ports, clock lines, and bus lines, and enhancing GND connections.
- Notebook PCs: Focuses on improving case shielding, GND connections, and installing EMI filters on LVDS cable connections and DC power supply inputs.
- USB Devices: Discusses noise suppression content and the effects of EMI filters on transmission signal waveforms.
- CD-ROM and DVD Drives: Emphasizes installing EMI filters on headphone output ports, clock lines, and bus lines.
- Printers and Fax Machines: Highlights improving GND, installing EMI filters on motor control lines, parallel interfaces, and DC power supply inputs.
- Car Navigators: Focuses on improving shielding and installing EMI filters on interface cable ports and clock lines.
- AC Power Supplies: Discusses noise emission status, suppression models, and effective suppression methods using hybrid choke coils.
- Mobile Phones: Covers installing EMI filters on LCD lines, DC power supply, data lines, and improving shielding.
The document details various components like Chip Ferrite Beads, Chip EMIFIL®, and Common Mode Choke Coils used in noise suppression. It also describes techniques like improving GND connections and shielding to reduce noise levels.
This guide provides a comprehensive overview of noise suppression techniques using EMI filters in various electronic devices, aiming to assist engineers in selecting appropriate components for effective noise management.
- Desktop PCs: Use of chip ferrite beads and by-pass capacitors to address noise from transient currents on power supply lines.
- Notebook PCs: Enhanced shielding with conductive plating and metal plates to improve grounding.
- USB Connections: Specific noise suppression measures for LS, FS, and HS modes using chip ferrite beads and common mode choke coils.
- CD-ROM Drives: Shielding with metal cases and additional suppression measures for headphone cables.
- Always read and adhere to ratings and cautions for storage, operating conditions, soldering, mounting, and handling.
- Ensure product specifications are approved before ordering to avoid discrepancies.
- Use of EMI filters on printer cable ports, DC power supply lines, and motor control lines to prevent noise conduction.
- Installation of ferrite beads on clock and bus lines to manage radiated noise.
- Car navigators are shielded with metal cases to prevent noise radiation, with EMI filters installed on all interface cables.
- Switching power supplies require noise filters, including common mode choke coils and capacitors, to suppress noise.
- Ensure proper installation of EMI filters and ferrite beads to achieve optimal noise suppression.
- Pay attention to the GND condition and impedance levels to enhance the effectiveness of noise suppression measures.
- Consult product specifications and approval sheets before ordering to ensure compatibility and performance.
Catalog excerpts
Note • Please read rating and CAUTION (for storage and operating, rating, soldering and mounting, handling) in this catalog to prevent smoking and/or burning, etc. • This catalog has only typical specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering. Noise Suppression by EMIFIL® Application Guide Application Manual
Open the catalog to page 1
Note • Please read rating and CAUTION (for storage and operating, rating, soldering and mounting, handling) in this catalog to prevent smoking and/or burning, etc. • This catalog has only typical specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering. Introduction To make effective noise suppression in electronic equipment it is necessary for design engineers to have a good understanding of the various types of EMI suppression filters available and the characteristics so that they can use suitable components....
Open the catalog to page 2
Note • Please read rating and CAUTION (for storage and operating, rating, soldering and mounting, handling) in this catalog to prevent smoking and/or burning, etc. • This catalog has only typical specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering. 1 Example of Noise Suppression in Desktop PCs 2 Example of Noise Suppression in Notebook PCs 3 Example of Noise Suppression for USB's 4 Example of Noise Suppression in CD-ROM Drives 5 Example of Noise Suppression in DVD Players 6 Example of Noise Suppression...
Open the catalog to page 3
Note • Please read rating and CAUTION (for storage and operating, rating, soldering and mounting, handling) in this catalog to prevent smoking and/or burning, etc. • This catalog has only typical specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering. 1 Example of Noise Suppression in Desktop PCs Noise Emission Status : Noise is emitted from the cables connected to a personal computer. When using a computer case that does not have efficient shielding, radiated noise from the computer body may sometimes cause...
Open the catalog to page 4
Note • Please read rating and CAUTION (for storage and operating, rating, soldering and mounting, handling) in this catalog to prevent smoking and/or burning, etc. • This catalog has only typical specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering. Example of Noise Suppression in Desktop PCs Noise Suppression Content in Personal Computers A PC contains many sources of noise inside and out, with many connected cables. Therefore, it is necessary to use EMI filters on the interface cables, in addition to shielding...
Open the catalog to page 5
Note • Please read rating and CAUTION (for storage and operating, rating, soldering and mounting, handling) in this catalog to prevent smoking and/or burning, etc. • This catalog has only typical specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering. Example of Noise Suppression in Desktop PCs Improving Shielding Parts of the metal case make contact with each other by surface contact, where fingers and gaskets are used where necessary to minimize the impedance of contact points at high frequencies. Overlaps...
Open the catalog to page 6
Note • Please read rating and CAUTION (for storage and operating, rating, soldering and mounting, handling) in this catalog to prevent smoking and/or burning, etc. • This catalog has only typical specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering. Example of Noise Suppression in Desktop PCs Example of effects produced when improving the GND and installing EMI filters on the cable connector port In the data above the GND is improved by increasing the number of connection points between the board and chassis,...
Open the catalog to page 7
Note • Please read rating and CAUTION (for storage and operating, rating, soldering and mounting, handling) in this catalog to prevent smoking and/or burning, etc. • This catalog has only typical specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering. Example of Noise Suppression in Desktop PCs Improving the GND on Extension Boards In case of installing an extension board with a cable, noise may conduct to the cable when GND noise level is high. This results in high-level noise radiation from the cable. Therefore,...
Open the catalog to page 8
Note • Please read rating and CAUTION (for storage and operating, rating, soldering and mounting, handling) in this catalog to prevent smoking and/or burning, etc. • This catalog has only typical specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering. 2 Example of Noise Suppression in Notebook PCs Noise Emission Status : Noise emission from PC body, LCD, connection cables, and connection cable between PC body and LCD. In notebook PCs, PCBs incorporate many signal lines with high-level noise. Generally, notebook...
Open the catalog to page 9
Note • Please read rating and CAUTION (for storage and operating, rating, soldering and mounting, handling) in this catalog to prevent smoking and/or burning, etc. • This catalog has only typical specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering. Example of Noise Suppression in Notebook PCs Noise Suppression Content in Notebook Personal Computers Notebook PC components are mounted in a limited space. Therefore, it is important to intensify the shielding condition as much as possible to suppress noise...
Open the catalog to page 10
Note • Please read rating and CAUTION (for storage and operating, rating, soldering and mounting, handling) in this catalog to prevent smoking and/or burning, etc. • This catalog has only typical specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering. Example of Noise Suppression in Notebook PCs Improving the Case Shielding and GND Connection Since plastic is usually used to encase a notebook PC, conductive plating is applied to the inside of the case. However, conductive plating alone is not sufficient for...
Open the catalog to page 11All Murata Electronics catalogs and technical brochures
High Voltage Resistors2 Pages
XMSSJE3G0PA-0035 Pages
MURATA PRODUCTS Lineup 2018164 Pages
Murata Products for Automotive13 Pages
MURATA PRODUCTS Lineup150 Pages
MURATA PRODUCTS Lineup136 Pages
Ceramic Resonators "CERALOCK®"46 Pages
Piezoelectric Sound Components28 Pages
Chip Monolithic Ceramic Capacitors182 Pages
Trimmer Capacitors39 Pages
MEMS Sensors4 Pages
Ceramic Resonators CERALOCK®32 Pages
EMI Suppression Filters for AC27 Pages
Magnetic Switch3 Pages
Chip Multilayer LC Filters9 Pages
SAW Traps1 Page
Archived catalogs
Rotary Position Sensors_201526 Pages
NTC Thermistors_202037 Pages
NTC Thermistors_201240 Pages
Chip Inductors (Chip Coils)_2019274 Pages
Rotary Position Sensors_201323 Pages
Chip Inductors (Chip Coils)_2013249 Pages
Pyroelectric Infrared Sensors22 Pages
Chip Monolithic Ceramic Capacitors220 Pages
Trimmer Potentiometers59 Pages
Crystal Resonator3 Pages
MURATA PRODUCTS 2010-2011423 Pages
NTC/PTC Thermistors for Automotive71 Pages
Trimmer Capacitors44 Pages
- Transformer
- Dry transformer
- Digital indicator
- Air blower
- Centrifugal blower
- DC-DC converter
- Encapsulated transformer
- Power transformer
- RF connector
- Electronic filter
- Radio antenna
- Coaxial connector
- Passive electronic filter
- Rectangular battery
- Murata ceramic capacitor
- Murata SMD capacitor
- Cylindrical battery
- Coupler