Protection with EMC Ferrites
Effective EMC protection is achieved by the insertion of ferrites. This article takes a quick look at four advantages of using Wurth Electronics ferrites.
Suppressing Unwanted Signals with EMC Ferrites
CE testing of electronic devices in the EMC lab clearly shows whether RF aspects were taken into account within the design process. Even at low clock frequencies e.g. in microprocessor-controlled devices, interferences can occur beyond the useful frequency range. These unwanted signals must be supressed. EMC ferrites are recommended for absorbing high frequency mains-borne interference as a means of retrospective suppression. These components are available in a variety of construction types and provide fast and cost-effective solutions. The performance of the final product is not affected as no redesign is required. Wire wound components and increasingly SMD ferrites are ideal for interference suppression on these circuits. These solutions offer an effective decoupling process directly at the source of interference.
How do EMC ferrites from Würth Elektronik assist in this case?
Ferrites used for EMC suppression are usually nickel-zinc. Their high surface resistance (>106 Ω)prevents leakage current or causing short-circuits. The special feature of these ferrites is that above 100 MHz, the real part of the loss resistance dominates.
The result is a whole series of advantages:
- As the ferrite operates as an ”absorber“ for frequencies above approx. 10 MHz, the useful signal is affected.
- The low-pass filter effect of wire wound ferrites or SMD ferrites is achieved solely by itself; no ground potential must exist as a third pole.
- Wideband interference suppression with just a single component.
- No capacitive influence on data or signal lines.
Ferrite Design Kits
Want to learn more about Ferrites? Visit our catalog where you can purchase our ferrite design kit and ask questions from the ferrite experts.
Click the links below to find these kits on the Digi-Key Website
Product Index > Kits > EMI, Filter Kits
Product Index > Kits > Inductor Kits
Information and media in this post was provided by Würth Elektronik.
Applicable Part Numbers
| DK Part # | Mfr Part # | Description | Series |
|---|---|---|---|
| 732-10084-ND | 742700 | EMI SUPPRESSION AXIAL FERRITE BE | WE-AFB |
| 732-10085-ND | 742711 | SNAP FERRITES | - |
| 732-10086-ND | 742841 | SMD FERRITES WE-CBF HF | WE-CBF |
| 732-10146-ND | 744230 | SMD COMMON MODE LINE FILTERS WE- | WE-CNSW |
| 732-10147-ND | 744630 | COMMON MODE POWER LINE CHOKES WE | WE-LF |
| 732-10148-ND | 744725 | SMD COMMON MODE LINE FILTERS | - |
| 732-10150-ND | 744800 | COMMON MODE POWER LINE CHOKES WE | WE-CMBNC |
| 732-10151-ND | 744821 | COMMON MODE POWER LINE CHOKES WE | WE-CMB |
| 732-10152-ND | 744825 | COMMON MODE POWER LINE CHOKES WE | WE-CMB, WE-CMBH |
| 732-10153-ND | 782013 | AXIAL EMI SUPPRESSION FERRITES W | Automotive, AEC-Q200, WE-AEFA |
| 732-10154-ND | 782792 | SMD EMI SUPPRESSION FERRITE BEAD | WE-CBA |
| 732-10180-ND | 760801 | POWER FACTOR CORRECTION CHOKES W | WE-PFC |
| 732-11546-ND | 74271151 | FERRITE 417OHM HINGED 15.01MM | Star-Tec |
| 732-11547-ND | 74271151S | FERRITE 417OHM HINGED 15.01MM | Star-Tec |
| 732-11548-ND | 74271251 | FERRITE 525OHM HINGED 24.99MM | Star-Tec |
| 732-11549-ND | 74271251S | FERRITE 525OHM HINGED 24.99MM | Star-Tec |
| 732-13172-ND | 74271733S | SNAP FERRITE W/FLEXIBLE CABLE FI | Star-Fix |
| 732-13448-ND | 74272142 | STAR-TEC LFS SNAP FERRITE WITH S | Star-Tec LFS |
| 732-13457-ND | 74272131 | STAR-TEC LFS SNAP FERRITE WITH S | Star-Tec LFS |
| 732-13458-ND | 74272132 | STAR-TEC LFS SNAP FERRITE WITH S | Star-Tec LFS |
| 732-13459-ND | 74272151 | STAR-TEC LFS SNAP FERRITE WITH S | Star-Tec LFS |
| 732-13460-ND | 74272211 | STAR-TEC LFS SNAP FERRITE WITH S | Star-Tec LFS |
| 732-13461-ND | 74272221 | STAR-TEC LFS SNAP FERRITE WITH S | Star-Tec LFS |
| 732-13462-ND | 74272222 | STAR-TEC LFS SNAP FERRITE WITH S | Star-Tec LFS |
| 732-13463-ND | 74272251 | STAR-TEC LFS SNAP FERRITE WITH S | Star-Tec LFS |
| 732-13464-ND | 7427014 | WE-TOF EMI SUPPRESSION TOROIDAL | WE-TOF |
| 732-13466-ND | 74270051 | WE-AFB EMI SUPPRESSION AXIAL FER | WE-AFB |
| 732-13468-ND | 74271633 | STAR-GAP SNAP FERRITE FOR RF APP | WE-STAR-GAP |
| 732-13478-ND | 7427141 | SNAP-RING SNAP FERRITE WITH PLAS | Snap-Ring |
| 732-13480-ND | 742701716 | WE-TOF EMI SUPPRESSION TOROIDAL | WE-TOF |
| 732-13483-ND | 74271622 | STAR-GAP SNAP FERRITE FOR RF APP | WE-STAR-GAP |
| 732-13485-ND | 742724759 | STAR-FLAT SNAP FERRITE WITH SAFE | WE-FLAT |
| 732-13783-ND | 7427502 | WE-UKW EMI SUPPRESSION 6-HOLE FE | WE-UKW |
| 732-13784-ND | 74275043 | WE-UKW EMI SUPPRESSION 6-HOLE FE | WE-UKW |
| 732-13785-ND | 7427504 | WE-UKW EMI SUPPRESSION 6-HOLE FE | WE-UKW |
| 732-13786-ND | 7427501 | WE-UKW EMI SUPPRESSION 6-HOLE FE | WE-UKW |
| 732-13787-ND | 74275013 | WE-UKW EMI SUPPRESSION 6-HOLE FE | WE-UKW |
| 732-13788-ND | 7427503 | WE-UKW EMI SUPPRESSION 6-HOLE FE | WE-UKW |
| 732-13789-ND | 74275022 | WE-UKW EMI SUPPRESSION 6-HOLE FE | WE-UKW |
| 732-13997-ND | 742722 | FLAT FERRITE CORES WE-FLAT | WE-FLAT |
| 732-14008-ND | 74271722S | STAR-FIX SNAP FERRITE WITH FLEXI | Star-Fix |
| 732-1499-ND | 7427246 | FERRITE CORE 194 OHM HINGED | Star-Flat |
| 732-1500-ND | 7427247 | FERRITE CORE 192 OHM HINGED | Star-Flat |
| 732-1501-ND | 7427248 | FERRITE CORE 180 OHM HINGED | Star-Flat |
| 732-1502-ND | 74272475 | FERRITE CORE 114 OHM HINGED | Star-Flat |
| 732-1503-ND | 74271112 | FERRITE CORE 321 OHM HINGED 6MM | Star-Tec |
| 732-1504-ND | 74271131 | FERRITE CORE 246 OHM HINGED | Star-Tec |
| 732-1505-ND | 74271132 | FERRITE CORE 241 OHM HINGED | Star-Tec |
| 732-1506-ND | 74271221 | FERRITE CORE 270 OHM HINGED | Star-Tec |
| 732-1507-ND | 74271222 | FERRITE CORE 265 OHM HINGED | Star-Tec |
| 732-1508-ND | 7427153 | FERRITE CORE 165 OHM HINGED 8MM | Star-Ring |
| 732-1509-ND | 7427151 | FERRITE CORE 119 OHM HINGED | Star-Ring |
| 732-1510-ND | 7427154 | FERRITE CORE 130 OHM HINGED 16MM | Star-Ring |
| 732-1511-ND | 7427155 | FERRITE CORE 110 OHM HINGED 27MM | Star-Ring |
| 732-1513-ND | 74271622S | FERRITE CORE 140 OHM HINGED | Star-Gap |
| 732-1514-ND | 74271633S | FERRITE CORE 100 OHM HINGED 8MM | Star-Gap |
| 732-1515-ND | 74270111 | FERRITE CORE 50 OHM SOLID 3.3MM | WE-TOF |
| 732-1517-ND | 742701121 | FERRITE CORE 123 OHM SOLID 5MM | WE-TOF |
| 732-1520-ND | 74270162 | FERRITE CORE 94 OHM SOLID 6.76MM | WE-TOF |
| 732-1522-ND | 74270117 | FERRITE CORE 161 OHM SOLID 10MM | WE-TOF |
| 732-1540-ND | 74270033 | FERRITE CORE 162 OHM SOLID | WE-AFB |
| 732-1541-ND | 74270030 | FERRITE CORE 158 OHM SOLID 5MM | WE-AFB |
| 732-1545-ND | 74270037 | FERRITE CORE 199 OHM SOLID 5.6MM | WE-AFB |
| 732-1551-ND | 74270034 | FERRITE CORE 160 OHM SOLID 7.3MM | WE-AFB |
| 732-1553-ND | 74270052 | FERRITE CORE 170 OHM SOLID 8MM | WE-AFB |
| 732-1558-ND | 74270091 | FERRITE CORE 170 OHM SOLID 9.5MM | WE-AFB |
| 732-1644-ND | 742792 | KIT DESIGN FERRITE CHIP BEAD | WE-CBF |
| 732-1913-ND | 74271722 | FERRITE CORE 270 OHM HINGED | Star-Fix |
| 732-1914-ND | 74271733 | FERRITE CORE 246 OHM HINGED 8MM | Star-Fix |
| 732-1915-ND | 742791 | KIT FERRITE SMD 1206-1812 SIZES | WE-CBF |
| 732-1916-ND | 742790 | KIT FERRITE SMD 0402-0805 SIZES | WE-CBF |
| 732-1920-ND | 744864 | KIT CHOKE FC SERIES | WE-FC |
| 732-2395-ND | 7427221 | FERRITE CORE 166 OHM SOLID | WE-FLAT |
| 732-2404-ND | 74272733 | FERRITE CORE 62 OHM HINGED 8MM | STAR-FIX LFS |
| 732-2405-ND | 742730021 | FERRITE BEAD 170 OHM RADIAL 4LN | WE-MLS |
| 732-2406-ND | 742730022 | FERRITE BEAD 248 OHM RADIAL 4LN | WE-MLS |
| 732-2407-ND | 74273002 | FERRITE BEAD 249 OHM RADIAL 4LN | WE-MLS |
| 732-2408-5-ND | 74273001 | FERRITE BEAD 264 OHM RADIAL 3LN | WE-MLS |
| 732-2409-5-ND | 742730023 | FERRITE BEAD 334 OHM RADIAL 4LN | WE-MLS |
| 732-3086-ND | 74272722 | FERRITE CORE 40 OHM HINGED | STAR-FIX LFS |
| 732-3090-ND | 7427727 | FERRITE CORE 100 OHM SOLID | WE-AFB LFS |
| 732-3302-ND | 74275812 | FERRITE CORE 200 OHM HINGED 5MM | STAR-BUENO |
| 732-3303-ND | 74275813 | FERRITE CORE 200 OHM HINGED | STAR-BUENO |
| 732-3304-ND | 74275815 | FERRITE CORE 350 OHM HINGED | STAR-BUENO |
| 732-3419-ND | 74271142 | FERRITE CORE 182 OHM HINGED 5MM | Star-Tec |
| 732-3420-ND | 74271142S | FERRITE CORE 182 OHM HINGED 5MM | Star-Tec |
| 732-3617-ND | 7427153S | FERRITE CORE 165 OHM HINGED 8MM | Star-Ring |
| 732-3619-ND | 74271222S | FERRITE CORE 265 OHM HINGED | Star-Tec |
| 732-3621-ND | 74271221S | FERRITE CORE 270 OHM HINGED | Star-Tec |
| 732-3623-ND | 74271132S | FERRITE CORE 241 OHM HINGED | Star-Tec |
| 732-3625-ND | 74271131S | FERRITE CORE 246 OHM HINGED | Star-Tec |
| 732-3627-ND | 74271112S | FERRITE CORE 321 OHM HINGED 6MM | Star-Tec |
| 732-3629-ND | 74271111S | FERRITE CORE 320 OHM HINGED 5MM | Star-Tec |
| 732-3635-ND | 7427151S | FERRITE CORE 119 OHM HINGED | Star-Ring |
| 732-3636-ND | 7427155S | FERRITE CORE 110 OHM HINGED 27MM | Star-Ring |
| 732-3637-ND | 7427154S | FERRITE CORE 130 OHM HINGED 16MM | Star-Ring |
| 732-3977-ND | 74270024 | FERRITE CORE 119 OHM SOLID | WE-SAFB |
| 732-3978-ND | 74270023 | FERRITE CORE 160 OHM SOLID 4MM | WE-SAFB |
| 732-3979-ND | 742700221 | FERRITE CORE 45 OHM SOLID 4MM | WE-SAFB |
| 732-3980-ND | 74270022 | FERRITE CORE 59 OHM SOLID 4MM | WE-SAFB |
| 732-3981-ND | 74270021 | FERRITE CORE 88 OHM SOLID 3MM | WE-SAFB |
| 732-3982-ND | 74270020 | FERRITE CORE 108 OHM SOLID 2.4MM | WE-SAFB |
| 732-3983-ND | 7427002 | FERRITE CORE 125 OHM SOLID 1.2MM | WE-SAFB |
| 732-3985-ND | 74270015 | FERRITE CORE 95 OHM SOLID 2MM | WE-SAFB |
| 732-3992-ND | 742700726 | FERRITE CORE 278 OHM SOLID 4MM | WE-SAFB |
| 732-3993-ND | 7427007141 | FERRITE CORE 45 OHM SOLID 2MM | WE-SAFB |
| 732-3996-ND | 74271111 | FERRITE CORE 320 OHM HINGED 5MM | Star-Tec |
| 732-7427143-ND | 7427143 | SNAP-RING SNAP FERRITE | - |
| 732-7427144-ND | 7427144 | SNAP-RING SNAP FERRITE | - |
| 732-78271111-ND | 78271111 | CAR-TEC SNAP FERRITE ; 316 ; 3.5 | WE-CAR-TEC |
| 732-78271111S-ND | 78271111S | CAR-TEC SNAP FERRITE ; 316 ; 3.5 | WE-CAR-TEC |
| 732-78271112-ND | 78271112 | CAR-TEC SNAP FERRITE ; 316 ; 4.5 | WE-CAR-TEC |
| 732-78271112S-ND | 78271112S | CAR-TEC SNAP FERRITE ; 316 ; 4.5 | WE-CAR-TEC |
| 732-78271131-ND | 78271131 | CAR-TEC SNAP FERRITE ; 235 ; 6.0 | WE-CAR-TEC |
| 732-78271131S-ND | 78271131S | CAR-TEC SNAP FERRITE ; 235 ; 6.0 | WE-CAR-TEC |
| 732-78271132-ND | 78271132 | CAR-TEC SNAP FERRITE ; 235 ; 7.0 | WE-CAR-TEC |
| 732-78271132S-ND | 78271132S | CAR-TEC SNAP FERRITE ; 235 ; 7.0 | WE-CAR-TEC |
| 732-9640-ND | 74271211 | FERRITE CORE 425 OHM HINGED 21MM | Star-Tec |
| 732-9641-ND | 74271211S | FERRITE CORE 425 OHM HINGED 21MM | Star-Tec |
| 7427114-ND | 7427114 | FERR SLV SNAP W/CASE 5.0MM GRY | SNAP-SLEEVE |
| 7427122-ND | 7427122 | FERRITE CORE 273 OHM HINGED | - |
| 74271833-ND | 74271833 | FERRITE CORE 113 OHM HINGED 8MM | Star-Gap |
| DK Part # | Mfr Part # | Description | Series |
|---|---|---|---|
| 732-1917-ND | 744028 | KIT INDUCTOR TPC SMALL SIZES | WE-TPC |
| 732-10155-ND | 744032 | SMD INDUCTORS WE-LQ | WE-LQ |
| 732-1918-ND | 744043 | KIT INDUCTOR TPC MED SIZES | WE-TPC |
| 732-1919-ND | 744062 | KIT INDUCTOR TPC LARGE SIZES | WE-TPC |
| 732-10159-ND | 744070 | SMD TINY POWER INDUCTORS WE-TPC | WE-TPC |
| 732-10174-ND | 744300 | SMD HIGH CURRENT FLAT WIRE INDUC | WE-HCM |
| 732-2229-ND | 744332 | KIT INDUCTOR WE-HCC SMD | WE-HCC |
| 732-10087-ND | 744705 | TOROIDAL LINE CHOKES WE-FI | WE-FI |
| 732-10088-ND | 744713 | ROD CORE INDUCTORS WE-SD | WE-SD |
| 732-1645-ND | 744720 | KIT DESIGN FOR LINEAR TECH | WE-PD for Linear Tech |
| 732-1923-ND | 744721 | KIT CHOKES FOR EXAR | |
| 732-1656-ND | 744722 | KIT INDUCTOR FOR MPS | WE-TPC |
| 744724-ND | 744724 | KIT DESIGN FOR NATIONAL REF | WE-PD for National Semiconductor |
| 732-4494-ND | 744728 | DESIGN KIT INDUCTORS FOR TI | |
| 732-10179-ND | 744731 | SHIELDED RADIAL LEADED WIRE WOUN | WE-TIS |
| 732-10177-ND | 744741 | RADIAL LEADED WIRE INDUCTORS WE- | WE-TI |
| 732-10178-ND | 744743 | RADIAL LEADED WIRE INDUCTORS WE- | WE-TI |
| 732-1926-ND | 744770 | KIT INDUCTOR PD SERIES LARGE | WE-PD |
| — | — | — | — |
| 732-10162-ND | 744773 | SMD POWER INDUCTORS WE-PD2 - 453 | WE-PD2 |
| 732-10163-ND | 744775 | SMD POWER INDUCTORS WE-PD2 - 785 | WE-PD2 |
| 732-1924-ND | 744777 | KIT INDUCTOR PD SERIES MED SIZES | WE-PD |
| 732-1925-ND | 744778 | KIT INDUCTOR PD SERIES SMALL | WE-PD |
| 732-744779-ND | 744779 | DESIGN KIT WE-PDF SMT SHIELDED P | WE-PDF |
| 732-10176-ND | 744870 | SEPIC APPLICATIONS WE-DD | WE-DD |
| 732-10175-ND | 744894 | SMD SHIELDED COUPLED INDUCTORS W | WE-TDC |
| 732-784701-ND | 784701 | DESIGN KIT PD2A & PD2SA SMT POWE | WE-PD2A |
| 732-784770-ND | 784770 | DESIGN KIT WE-PDA SMT POWER INDU | WE-PDA |
| 732-10164-ND | 784773 | SMD POWER INDUCTORS WE-PD2A - 45 | WE-PD2A |
| 732-10165-ND | 784775 | SMD POWER INDUCTORS WE-PD2A - 78 | WE-PD2A |
| 732-784778-ND | 784778 | WE-PDA SMT POWER INDUCTOR 2 SIZE | WE-PDA |
| 732-10156-ND | 7440402 | SMD POWER INDUCTORS WE-LQS - 252 | WE-LQS |
| 732-10157-ND | 7440405 | SMD POWER INDUCTORS WE-LQS - 504 | WE-LQS |
| 732-10160-ND | 7440894 | SMD POWER INDUCTORS WE-SPC | WE-SPC |
| 732-10161-ND | 7447713 | SMD POWER INDUCTORS WE-PD - 1030 | WE-PD |
| 732-10084-ND | 742700 | EMI SUPPRESSION AXIAL FERRITE BE | EMI SUPPRESSION AXIAL FERRITE BE |
| 732-10085-ND | 742711 | SNAP FERRITES | SNAP FERRITES |
| 732-10086-ND | 742792 | KIT DESIGN FERRITE CHIP BEAD | KIT DESIGN FERRITE CHIP BEAD |
| 732-10153-ND | 742841 | SMD FERRITES WE-CBF HF | SMD FERRITES WE-CBF HF |
| 732-10154-ND | 782792 | SMD EMI SUPPRESSION FERRITE BEAD | SMD EMI SUPPRESSION FERRITE BEAD |
| 732-13997-ND | 742722 | FLAT FERRITE CORES WE-FLAT | FLAT FERRITE CORES WE-FLAT |
| 732-1644-ND | 782013 | AXIAL EMI SUPPRESSION FERRITES W | AXIAL EMI SUPPRESSION FERRITES W |
| 732-1915-ND | 742791 | KIT FERRITE SMD 1206-1812 SIZES | KIT FERRITE SMD 1206-1812 SIZES |
| 732-1916-ND | 742790 | KIT FERRITE SMD 0402-0805 SIZES | KIT FERRITE SMD 0402-0805 SIZES |
| 732-10184-ND | 744762A/RFI | FERRITE SMD INDUCTORS WE-RFI | WE-RFI |