Ferrite Bead symbol and reference designator
Printed From: PCB Libraries Forum
Category: Libraries
Forum Name: Schematic Symbols
Forum Description: [General or a CAE specific issues / discussions]
URL: https://www.PCBLibraries.com/forum/forum_posts.asp?TID=2271
Printed Date: 03 Nov 2025 at 4:59pm
Topic: Ferrite Bead symbol and reference designator
Posted By: bnoel
Subject: Ferrite Bead symbol and reference designator
Date Posted: 20 Dec 2017 at 8:29am
|
Hello, I am seeing some conflicting information online regarding Ferrite Beads. I see some documentation that shows the schematic symbol for a Ferrite Bead as an Inductor with a reference designator of L and other documentation that shows the symbol as in the inserted image with the reference designator of FB. What is the definitive symbol and ref des?
|
Replies:
Posted By: Tom H
Date Posted: 20 Dec 2017 at 8:45am
|
Here is a list of common ref des for the past 30 years - https://www.pcblibraries.com/forum/common-pcb-reference-designators_topic728.html" rel="nofollow - https://www.pcblibraries.com/forum/common-pcb-reference-designators_topic728.html They have the same electrical function: "L" covers Inductors, Beads, Ferrite Beads, Chokes, Common Mode Chokes and all parts related to the function of an electric or electronic circuit that possesses inductance used in order to filter common mode electromagnetic interference (EMI) currents without de-rating under high currents and without causing signal degradation. Or, the geometry and electromagnetic properties of coiled wire over the ferrite bead result in an impedance for high-frequency signals, attenuating high frequency EMI/RFI electronic noise. I guess you can use FB for Ferrite Bead. Sounds good to me. ------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - X - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn |
Posted By: tgrodnicki
Date Posted: 21 Dec 2017 at 12:28am
"Error 404: Page was Moved!" In document from 2004 created by PCB Libraries and titled Standard Reference Designators "FB" stands for Ferrite Bead. I followed standard from this publication. In document from 2009 created by PCB Matrix and tltled IPC-7351B Naming Convention for Standard SMT Land Patterns in section PCB Matrix Naming Convention for Non-Standard SMT Land Patterns land pattern name for Ferrite Beads is FB_Mfr.'s Part Number. Current version of lattter document does not have section for non-standard patterns. |
Tom H wrote:Posted By: Nick B
Date Posted: 21 Dec 2017 at 2:26am
|
I don't know where the temporary link came from, but I modified Tom's post with the proper link.Please try again... ------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - X - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn |
Posted By: LarryJoy
Date Posted: 28 Aug 2018 at 2:29am
|
The IEC 60617 graphic symbol for a Ferrite Bead is shown in IEEE 315A, Clause 6.2.11 as follows: In addition the class letter to use in a ref des is E. See IEEE 315, Clause 22.4. |
Posted By: Tom H
Date Posted: 27 Jun 2024 at 9:42am
|
Class Designation Letters for Reference Designations A Separable Assembly AR Amplifier AT Attenuator; Isolator B Blower, Motor BT Battery C Capacitor CB Circuit Breaker CP Connector Adapter, Coupling CN Capacitor Network CR Breakdown Diode D Diode DC Directional Coupler DL Delay Line DS Display, Lamp E Terminal F Fuse FD* Fiducial FL Filter G Generator, Oscillator GN General Network H Hardware HY Circulator J Connector, Jack, Female K Contactor, Relay L Coil, Inductor, Bead, Ferrite Bead LS Loudspeaker, Buzzer M Meter MG Motor-Generator MH* Mounting Hole MK Microphone Q Transistor MP Mechanical Part P Connector, Plug, Male PS Power Supply R Resistor RN Resistor Network RT Thermistor RV Varistor, Variable Resistor S Switch TZ Transzorb T Transformer TB Terminal Board, Terminal Strip TC Thermocouple TP** Test Point, In-circuit Test Points U Inseparable Assembly, IC Pkg VR Voltage Regulator W Wire, Cable, Cable Assembly X Fuse holder, Lamp holder, Socket Y Crystal, Oscillator Z Miscellaneous *These class letters would not appear in a parts list as they are part of a PCB and not an active electronic component. **Not a class letter, but commonly used to designate test points for maintenance purposes. Note:
The above list is not exhaustive. See the standard list of class designation
letters in ANSI Y32.2/IEEE Std. 315, Section 22 and the Index. ------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - X - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn |