RF Inductors

Token Cuts Inductor Size and Cost

Token utilizes the latest technology enabling the most cost-effective designs in manufacturing inductors. The 0402, 0603, 0805, 1206, 1210, to 1812 series of RF Miniature Inductors all contain wirewound or multi-layer technology with material substrate in ceramic or ferrite cores. Thus providing economic cost with the ultimate performance demanded by today's RF applications. Inductors feature high Q factor, SRFs (self-resonant or series resonant frequency), and Idc (maximum current carrying capacity). RF Inductor product catalogue is avaiable to download at PDF file (1.86MB).

How to quickly search RF inductors for all of the characteristics?

Searching and comparing data sheets of inductor manufacturers can be time consuming.
Token’s Parameter Sorting Search Mode allows selection of inductors based on different parameters. To enter Searching Mode:

  • By entering just the inductance value,
  • By sorting parameter to narrow down searching range,
  • Or by enter keyword / part number / size dimensions L*W*H to partial or exact searching.

Inductors Selection Notes:

For choke applications, the SRFs (self-resonant or series resonant frequency) is the frequency that provides the best signal blocking.

  • At the SRF, impedance is at its maximum.
  • At frequencies below the SRF, impedance increases with frequency.
  • At frequencies above the SRF, impedance decreases with frequency.

For higher order filter or impedance matching applications, in general, the choice of inductance value typically determines the SRF and vice versa. The higher the inductance value, the lower the SRF, due to increased winding capacitance. It is more important to have a relatively flat inductance curve (constant inductance vs. frequency) near the required frequency. This suggests selecting an inductor with an SRF well above the design frequency. A rule of thumb is to select an inductor with an SRF that is a decade (10X) higher than the operating frequency.

What is Q factor? High Q leads to low insertion loss, minimizing power consumption, and narrow bandwidth. It is important if the inductor is to be used as part of an LC (oscillator) circuit or in narrow bandpass applications. In general, wirewound inductors have much higher Q values than multilayer inductors of the same size and value. Token's material science and manufacturing expertise effectively bridges the gap between wire-wound performance and multi-layer inductors with its TRMF100505 (EIA 0402) and TRMI160808 (EIA 0603) series.

How does current requirement affect inductor? Higher current requires larger wire or more threads of the same wire size to keep losses and temperature rise to a minimum. Larger wire lowers the DCR and increases the Q factor. Using a ferrite core inductor with a lower turn count can achieve higher current capacity and lower DCR. Ferrite, however, may introduce new limitations such as larger variation of inductance with temperature, looser tolerances, lower Q, and reduced saturation current ratings. Token's ferrite inductors with open magnetic structures, will not saturate, even at full rated current.

RF Wirewound Inductors

ThumbnailDescription Type DCR (Ω) Inductance (μH)

  • 1 (TREC) RF Chip Wire Wound Inductors Narrow Pad, High Current 0.11~13.00 1.00~330.00 Molded Type Wirewound Chip Inductors feature high resistance to heat, humidity, mechanical shocks and presser. Accurate dimensions for automatically surface mounted. Token TREC Series is primarily designed for chip narrow pad, high current, molded type, wire wound inductors and offers improved performance in the same compact case size. Product conforms to the RoHS directive and Lead-free. The TREC series chip inductor can be customed designs for tighter tolerances on request.
    Download (TREC) Series - PDF (358KB)

  • 2 (TREM) RF High SRFs Inductors Narrow Pad 0.18~40.00 0.10~1000.00 (TREM) RF High SRFs series high reliable wire would chip inductors for communication, equipment, instrument, video & audio have been developed in response to the trend toward higher density mounting of parts in electric circuits. Token TREM Series is primarily designed for chip narrow pad, high SRFs, molded type, wire wound inductors and offers improved performance in the same compact case size.
    Download (TREM) Series - PDF (390KB)

  • 3 (TRAD) Surface Mount Air Core Inductors Non-Flat Top Air Core Custom Custom Token's ultra-miniature single layer coil has two advantages. Firstly, like all air core coils, it is free from iron losses and the non-linearity. Secondly, single layer coils have the additional advantage of low self-capacitance and thus high self-resonant frequency. Air Coils is known as "Spring Coils". Token manufactures all types of air coils inductors.
    Download (TRAD) Series - PDF (345KB)

  • 4 (TRAM) Surface Mount Spring Inductors | P2 SMD Flat Top Air Core 2.60m~63.40m 0.00165~0.538 The latest range of air core surface mount spring coils from Token is fully compliant with RoHS legislation and available immediately in full production volumes. The TRAM series provides a cost effective and miniaturised alternative to the earlier version. The wire-wound construction with a miniature core is ideal for high frequency applications. These new SMD coils measure 1.8 x 2.0 mm with a low 2.0 mm profile, which combined with a mould-sealed surface, makes them particularly suitable for high-density mounting.
    ... More Page (TRAM) 2. Download (TRAM) Series - PDF (368KB),

  • 5 (TRWL) Wire Wound Ceramic Chip Inductors | P2 High Current, Low Profile 0.02~11.50 0.002~15.00 Token TRWL series is a wire wound and ceramic technology that offers the highest usable frequency range, highest current carrying capability, and the best Q factor of the three technologies. The combination of these three advantages ensure that design engineers will have the right product for many more high frequency applications than most competitors. High frequency inductors are specifically used for their frequency dependent properties. Depending on the technology, size and inductance value, the inductor will pass a certain desired range of frequencies, but will block or attenuate frequencies above the desired range. This eliminates high frequency noise or interference from communications signals. ... More Page (TRWL) - 2.
    Download (TRWL) Series - PDF (608KB)

  • 6 (TRCM) Wire Wound SMD Inductors Wide Pad 0.18~40.00 0.10~1000.00 Molded-Type Chip RF Wirewound Inductors feature high resistance to heat, humidity, mechanical shocks and pressures. Miniaturisation of today's electrical and electronic devices requires component manufacturers to increase the performance of components without increasing footprint. Token TRCM series utilities wirewound technology that offers wide Pad inductor with the highest SRF carrying capability, highest usable frequency range, and the best Q factor of the narrow pad TREM and TREC series.
    Download (TRCM) Series - PDF (386KB)

  • 7 (TR4308I) RFID Coils Series RFID Transponder 7.4~123.0 0.40~8.10 Token TR4308I transponder coil series is specified for RFID applications for the best performing designed at 125 kHz. The TR4308I covers a wide range of electrical performances and offers better sensitivity, greater read distance and higher SRF than other coils its size. Radio Frequency Identification (RFID) is the system of using radio signals to send information identifying a particular situation or item. Token TR4308I is suited for wireless data transmission in low frequency RFID products, such as immobilizers, TPMS, keyless entry. Other industrial applications include access control and tracking devices.
    Download (TR4308I) Series - PDF (395KB)

RF Thin Film & Multilayer Inductors

ThumbnailDescription Type DCR (Ω) Inductance (μH)

  • 1 (TRAL) Thin-Film Inductors Thin Film 0.35~7.50 0.001~0.10 Token TRAL chip thin-film inductors provide reliable protection against challenging EMI problems in high frequency filtering applications. This miniature wirewound inductor features a low seated height that stands only 0.23mm above the circuit board. It protects sensitive electronic circuitry and ensures high performance operation in a wide range of compact devices that are shrinking ever smaller in physical size. TRAL series uses a thin-film technology for high reliability and precision tolerances to 1% or ±0.1nH. The TRAL thin-film inductor series is available in 0603, 0402, and 0201 sizes, in inductance values from 0.1 to 100nH, in tolerances down to 0.1nH or 1%, and with SRF (self-resonant frequency) tightly controlled.
    Download (TRAL) Series - PDF (422KB)

  • 2 (TRMA) Multilayer Ferrite Beads Chip Inductors High Current 0.03~1.00 - Token TRMA series multilayer ferrite bead inductor is one popular high current version of Token chips products. Ceramic materials and process technologies have allowed Token to lower the DC resistance of its chip ferrite beads, increasing rated current to create the TRMA series. With a maximum current rating of up to 6A and a wide operating temperature range of between -55°C and +125°C, the TRMA series is ideally suited to applications in harsh environments. The series comes in 0402 size packaging (1 x 0.5 x 0.5 mm), for designers seeking to reduce board space without performance degradation. Low DC resistance also helps reduce power consumption for battery-powered applications.
    Download (TRMA) Series - PDF (419KB)

  • 3 (TRMB) RF Multilayer Bead Inductors | P2 High Speed Signals 0.03~1.00 - Token Electronics has introduced the TRMB Series, a family of twelve multilayer chip bead inductors offering high impedance. The TRMB Bead series is a multilayer technology with good overall characteristics in a cost effective package. In addition, TRMB parts offer a high-performance noise-filtering capability over a wide range of high frequencies. In systems that currently use multiple narrow-band inductors to cover a wide frequency range, the TRMB can provide the same function in a single chip, reducing component count and board area. The TRMB multilayer inductor series is available in 1812, 1806, 1210, 1206, 0805, 0603, and 0402 sizes in three catalogs, standard, low profile, and High Speed Signals. This product provides a good addition of electrical performance and low cost. ... More Page (TRMB) 2.
    Download (TRMB) Series - PDF (477KB)

  • 4 (TRMF) RF Multilayer Ceramic Inductors High Frequency 0.10~2.10 0.0012~10.00 Ceramic materials and process technologies have allowed Token to add magnetics portfolio with a new series of multilayer high-frequency ceramic inductors. The Token TRMF series inductors are aimed at signal shaping and RF filtering applications in a wide range of electronic systems. Target end products include remote controls, high-end video processing equipment, set-top boxes, cell phones, pagers, keyless entry systems, wireless and wireline networks, and cable modems. Standard inductance options for the TRMF series range from 1 nH to 100 nH. Available tolerances are ±0.3nH, ±5%, and ±10%. Maximum DC resistance (DCR) ranges from 0.1Ω to 2.5Ω depending on inductance. In a space-saving surface-mount 0402 package measures (1 x 0.5 mm) and with 2-mil (0.5 mm) height profile. 0402, 0603, and 0805 package size are available.
    Download (TRMF) Series - PDF (724KB)

  • 5 (TRMI) Chip Multilayer Ferrite Inductors Chip Ferrite 0.10~2.10 0.0012~10.00 The TRMI devices utilize closed magnetic circuit construction to avoid crosstalk. These are suitable for EMI reduction on DC power lines and low speed signal lines where the smaller packaging reduces board space. Conform to the RoHS directive and Lead-free. Package of multilayer Ferrite TRMI chip is suitable for automatic pick and place equipment and is mounted in a surface mount package which assures mechanical stability and excellent lead coplanarity. Token TRMI series is a multilayer ferrite technology with good overall characteristics in a cost effective package. The TRMI multilayer inductor series is available in 0603, 0805, and 1206 sizes. Inductance values range from 10 to 33000nH, and tolerances are as tight as ±10%.
    Download (TRMI) Series - PDF (407KB)

Technical Application Notes For Inductors And Chokes

Selecting The Optimum Indcutor Choke to Best Match The Right Performance

Inductive components store energy intermittently in switch-mode power supplies and DC/DC converters, form parts of RF circuits or RFID systems, transform current/voltage, match impedances, are filter elements and last but not least interference suppression components to ensure EMC.

The requirements on inductors depend on how and where they are used. RF circuits need coils with high quality factors and resonant frequencies. EMC applications require high inductance to achieve good interference suppression characteristics, low Q factors being more desirable here due to the need to avoid resonance.

Token Electronics provides suitable inductive components for all applications. This quide contains a wide selection of standard components, from SMT types through high current inductors for power electronics applications to transformers.

Comparision of Inductor Factors for Applications
Applications Inductance Current
Rating
Resonance
frequency
Q factor DC
Resistance
RF Circuits, Resonant Circuits low low very high very high low
EMC high high high low very low
RFID depends on the specific application low high high low
DC/DC Converters depends on the specific application high medium high low
Transformers in DC/DC depends on the specific application depends on the specific application medium depends on the specific application low
Signal Processing depends on the specific application low high - medium

RF Circuits

The Token RF product range of SMT and leaded RF chokes are especially suitable for RF and other high frequency circuits. Typical applications are resonant circuits and frequency-selective filters of the type increasingly used in telecommunications engineering and automotive electronics.

Filter Circuits

When inductive components are used for filters in power supplies for electronics, high inductance, the lowest possible DC resistance and a low Q factor are required. The impedance should have a wideband frequency characteristic. In addition to the current rating, the maximum permissible pulse current (switching transient currents) and adequately high core material saturation are important.

RFID Systems

RFID systems allow contactless identification without direct line-of-sight contact. They are used for wireless data transmission in a range of a few meters. Examples of their application include the automobile industry, logistics, agriculture, medical engineering and security systems. The range of Token transponder coils is especially designed for high mechanical stability and high sensitivity as required in the automobile industry for immobilizers, car access systems and tire pressure monitoring systems (TPMS).

DC/DC Converters, Switch-Mode Power Supplies

Inductive components are used for magnetic energy storage in all kinds of DC/DC converters and switch-mode power supplies. Depending on application, a broad range of different components starting from high-current RF and SMT power inductors up to toroid chokes and transformers can be used.

Signal Processing

Among other things, signal transformers are notable for being able to transform signals in a large frequency range. They are consequently used in particular in high-speed data transmission (e.g. xDSL) for matching and electrical isolation. Innovative materials and a special winding and coil former design result in low losses, good total harmonic distortion, and fulfilling the requirements on creepage and clearance distances.

EMC Application

For broadband interference suppression, current-compensated chokes with different core shapes are especially suitable, e.g. ring or D cores and powder core chokes.

Apart from use as filters in mains and other power supply lines, such chokes are important for data lines as used in telecommunications engineering, in line cards, in telephone exchanges (digital and analog), in automotive electronics, and CAN bus applications.

Almost all component families are approved in accordance with the main international standards. All chokes for low-frequency mains networks are dimensioned and tested in compliance with applicable EN and IEC standards.