What are the different types of inductors?

2023-12-01

According to inductors’ construction, purpose, and design, we can divide them into several types, like Wirewound Inductors, SMD inductors, RF inductors, power inductors etc.

Let’s know more details. Firstly what is an inductor? 

An inductor, also known as a coil or reactor, is a passive electrical component that stores energy in a magnetic field when electric current flows through it. It typically consists of a conducting wire wound into a coil, and the strength of the induced magnetic field is directly proportional to the number of turns in the coil and the current passing through it. The property that defines an inductor is called inductance, measured in henries (H), which quantifies the amount of magnetic flux generated for a given electric current. Inductors are used in electronic circuits to provide inductance, which can filter signals, store energy, block AC while allowing DC to pass, and create resonance circuits, among other uses.

How many types of inductors are there, and their main characteristics? 

There are several types of inductors, each designed for specific applications and characteristics. Some common types of inductors include:

1-- Wirewound Inductors: These are made by winding a conductive wire around a core, typically made of ceramic, ferrite, or iron powder. They are one of the most common types of inductors used in electronic circuits.

The main features of wirewound inductors include: High Inductance, High Current Capability, Low Resistance, Good Thermal Performance etc.

Althought with many advantages, wirewound inductors may have size constraints due to their construction; they are typically larger than their non-wirewound counterparts. Additionally, for some high-frequency applications, the wire windings can introduce parasitic capacitance and additional inductive components, leading to a less ideal inductor performance.

HONGDA Capacitors offer various inductors, our main wirewound inductors include: HDTC HDTF series.

These inductors are widely used in micro TV, LCD TV, video camera, portable VRC, car audio, thin radio, TV tuner, mobile phone, etc.

2-- SMD (Surface Mount Device) Inductors: These are compact inductors designed for surface-mounted applications on printed circuit boards (PCBs).

Their main features: 

2.1 Miniaturization: SMD inductors are designed to be small in size to fit the compact layout of modern electronic devices.

High Frequency Performance: They are suitable for high-frequency applications with minimal signal loss.

2.2 Low Profile: Their low height profile allows them to be used in applications with space constraints.

2.3 Inductance Range: They offer a wide range of inductance values, accommodating various circuit requirements.

2.4 Current Rating: These inductors are available with different current ratings to support a variety of power requirements.

2.5 Tolerances: They come with varying inductance tolerances for different precision needs.

2.6 Magnetic Shielding: Many SMD inductors are magnetically shielded to reduce electromagnetic interference (EMI) with other components.

2.7 Materials: They are made from various materials, such as ferrite or metal alloy cores, which affect their performance characteristics like Q factor and saturation current.

2.8 Mounting: They are designed for surface mounting, which makes them suitable for automated pick-and-place manufacturing processes, thus reducing assembly costs.

2.9 Environmental Resistance: SMD inductors are often constructed to be highly resistant to harsh environments, including changes in temperature, humidity, and mechanical shock.

HONGDA Capacitors offered mostly is SMD inductors, like SMD power inductors(HPIT  HPIM HAPM HPIA HDSDRH HDSD HDCDRH, etc series)

Cross: Murata TDK Wurth Sumida 

Widely used on Power Supplies, RF Communications, Mobile Devices, Computer Motherboards, Automotive Electronics etc.

3-- RF (Radio Frequency) Inductors: These are specifically designed for high-frequency applications and have low resistance and capacitance values, main feature including:

3.1 Quality Factor (Q Factor): They have a high Q factor, which indicates low energy loss relative to the inductor's reactance. A higher Q factor translates to lower resistance and higher efficiency in RF circuits.

3.2 Self-Resonant Frequency (SRF): RF inductors have a specified self-resonant frequency, beyond which the inductor stops behaving inductively and starts to act capacitive. It is crucial to choose an RF inductor with an SRF well above the operating frequency.

3.3 Impedance: They provide the required impedance at a specific frequency to ensure the desired filtering, impedance matching, or resonance in RF applications.

3.4 Magnetic Shielding: RF inductors are often magnetically shielded to minimize electromagnetic interference (EMI) that can affect other components in a dense circuit board layout commonly found in RF applications.

3.5 Low ESR: They typically feature low equivalent series resistance (ESR), which is important in reducing power losses and heat generation at high frequencies.

3.6 Compact Size: Given the constraints in RF applications, these inductors are designed to be compact, allowing them to fit into tight spaces without compromising performance.

3.7 Stability: RF inductors are designed to maintain their inductance over a range of operating conditions, temperature variations, and through the presence of a DC bias current.

3.8 Materials: They are constructed from materials with low loss at high frequencies, such as ceramic or high-frequency ferrite materials.

3.9 Mounting: Similar to other SMD components, RF inductors are designed for surface mounting, which facilitates automated assembly and soldering processes.

HONGDA Capacitors main RF inductors include: HDTC, HTF series.

HDTC: ceramic high Q inductors. HDTC0402  HDTC0603  HDTC0805  HDTC3225...available

HTF: Ferrite high Q inductors. HDTF0402  HDTF0603  HDTF0805... available

4-- Power Inductors: These are inductors capable of handling high currents and are commonly used in power supply circuits and energy storage applications.

Key features include: 

4.1 Inductance Range: Power inductors possess a wide range of inductance values suitable for filtering, energy storage, and smoothing in power circuits.

4.2 Low Core Losses: They are designed to have low eddy current and hysteresis losses at the frequencies they operate at, contributing to better efficiency in power conversion applications.

4.3 Size and Footprint: Power inductors come in various sizes to cater to different power levels and space constraints on circuit boards.

4.4 Frequency Performance: Their performance is optimized for the lower frequency range where power circuits typically operate, such as switching frequencies for DC-DC converters.

4.5 Durable Construction: They are robustly constructed to withstand mechanical and thermal stresses during operation and in the context of power electronics applications.

HONGDA Capacitors provide HPIT HPIM HAPM HPIA HDSDRH HDSD HDCDRH etc power inductors.

Replace: TDK Murata Wurth Taiyo Yuden Vishay etc. 

Above is just listed the main inductors. More series available.

HONGDA Capacitors, as the leading inductors factory in China, factory with ISO9001 qualification, can provide the high quality, cost-effective parts to you.

Our strength include, but no limited to below.

1.Competitive prices: much better than Murata TDK;

2.Reliable quality and short lead time: competitors lead time 34+weeks, our lead time: 5weeks

3.Engineer cross: our sales team together with engineer will do cross for you.

4.Fast response and good support: we provide free samples for good customer and project.

Welcome to email sandy@hongdacap.com.hk for inductors catalog and cross reference.