Classification and Characteristics Analysis of Inductors
Inductance, as a storage component for electromagnetic energy, can be classified from different dimensions. The following is an original classification system that combines physical characteristics and application scenarios to systematically sort out the types of inductors:
1、 Classification by magnetic core material and structure
Hollow core inductor
Features: Non magnetic material filling, low inductance, no magnetic saturation problem.
Application: High frequency circuits (such as RF matching), low loss scenarios.
Closed magnetic circuit inductance
Magnetic core type: closed ring structure such as ferrite, amorphous alloy, etc.
Characteristics: High inductance, low magnetic leakage, but prone to saturation.
Applications: power filtering, high current energy storage.
Open magnetic circuit inductor
Magnetic core types: linear structures such as rod-shaped ferrite and silicon steel sheets.
Features: Non closed magnetic circuit, strong anti saturation ability, but low efficiency.
Application: Low frequency choke coil, motor drive circuit.
2、 Classified by manufacturing process
Wound inductor
Process: The wire is wound around the magnetic core or skeleton.
Features: Wide inductance range, able to withstand high currents, but with a large volume.
Application: high-power power supply, industrial equipment.
Multilayer Chip Inductors (MLCC Inductors)
Process: Ceramic media and metal electrodes are alternately laminated.
Features: Small size, excellent high-frequency characteristics, but low current capacity.
Application: Decoupling and filtering of mobile phones and high-speed digital circuits.
Thin film inductor
Process: Deposition of magnetic thin film on substrate and photolithography molding.
Features: High precision, small parasitic parameters, suitable for high-frequency integration.
Applications: RF modules, microwave circuits.
3、 Classified by functional purpose
Energy storage inductor
Core requirements: High energy density and anti saturation ability.
Scenario: DCDC converters and inverters for switching power supplies.
Filter inductor
Design focus: Suppress noise in specific frequency bands.
Type:
Common mode inductance: eliminates common mode interference (such as USB interface filtering).
Differential mode inductor: filters out differential mode noise (such as power input filtering).
Resonant inductor
Function: Form an LC resonant circuit with a capacitor.
Applications: wireless charging, RF oscillation circuit, tuned amplifier.
4、 Classified by adjustability
Fixed inductance
Features: Factory cured inductance, high reliability.
Scenario: Standardized circuit design (such as surface mount inductors).
Variable inductance
Adjustment method: Mechanical adjustment of magnetic core position or electronic tuning.
Application: Radio tuning circuit, impedance matching network.
5、 Classified by packaging form
Plug in inductor
Features: Pin insertion into PCB, good heat dissipation but occupies a large space.
Scenario: Industrial control equipment, traditional power supply design.
Surface mount inductors (SMD)
Features: Surface mount, suitable for automated production.
Subdivision: power chip inductors (high current), high-frequency chip inductors (low loss).
Integrated inductance module
Design: Inductors and other components (capacitors, ICs) are packaged as system level modules.
Applications: automotive electronics, miniaturized consumer electronics.
The classification of inductors requires comprehensive consideration of materials, processes, functions, and scenarios. Hollow core and magnetic core inductors distinguish energy density, winding and thin film processes correspond to different frequency band requirements, while functional classification directly points to circuit design goals. Reasonable selection requires balancing inductance, frequency response, current capacity, and volume limitations to achieve optimal circuit performance.
