Fixed Inductors

Part Number	Description / PDF	Quantity
L-05B18NKV6T Johanson Technology	FIXED IND 18NH 200MA 1.5 OHM SMD	0
L-14WR10JV4E Johanson Technology	FIXED IND 100NH 400MA 630 MOHM	0
L-14W12NGV4E Johanson Technology	FIXED IND 12NH 700MA 130 MOHM	0
L-14C47NJV4T Johanson Technology	FIXED IND 47NH 300MA 1 OHM SMD	34907
L-07W8N7KV4T Johanson Technology	FIXED IND 8.7NH 480MA 200 MOHM	0
L-07CR12KV6T Johanson Technology	FIXED IND 120NH 100MA 2.5 OHM	0
L-14WR33JV4E Johanson Technology	FIXED IND 330NH 150MA 3.6 OHM	0
L-15WR39JV4E Johanson Technology	FIXED IND 390NH 210MA 2.2 OHM	0
L-07W15NKV4T Johanson Technology	FIXED IND 15NH 560MA 172 MOHM	0
L-15W56NKV4E Johanson Technology	FIXED IND 56NH 500MA 250 MOHM	0
L-07C7N5JV6T Johanson Technology	FIXED IND 7.5NH 250MA 400 MOHM	95
L-14W47NGV4E Johanson Technology	FIXED IND 47NH 600MA 280 MOHM	0
L-14WR12JV4E Johanson Technology	FIXED IND 120NH 300MA 650 MOHM	0
L-14C6N8JV4T Johanson Technology	FIXED IND 6.8NH 300MA 350 MOHM	112032
L-15WR33GV4E Johanson Technology	FIXED IND 330NH 300MA 1.65 OHM	0
L-07W30NJV4T Johanson Technology	FIXED IND 30NH 400MA 300 MOHM	0
L-14W27NKV4E Johanson Technology	FIXED IND 27NH 600MA 220 MOHM	0
L-14C68NKV4T Johanson Technology	FIXED IND 68NH 300MA 1.2 OHM SMD	0
L-14W7N5JV4E Johanson Technology	FIXED IND 7.5NH 700MA 110 MOHM	0
L-15W22NKV4E Johanson Technology	FIXED IND 22NH 600MA 100 MOHM	0

Fixed Inductors

1. Overview

Fixed inductors are passive electronic components designed to store energy in magnetic fields when electrical current flows through them. Unlike variable inductors, their inductance values remain constant during operation. These components play critical roles in filtering, signal processing, energy storage, and electromagnetic interference (EMI) suppression across modern electronics, including power supplies, communication systems, and automotive electronics.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
Wirewound Inductors	High precision, high current handling, low resistance	Power supplies, DC-DC converters
Chip Inductors	Compact SMD package, stable performance at high frequencies	Mobile devices, RF circuits
Ferrite Bead Inductors	Effective high-frequency noise suppression	EMI filtering in digital circuits
Thin-Film Inductors	Ultra-compact, high Q-factor, tight tolerance	5G communication modules, IoT devices

3. Structure and Composition

Typical fixed inductors consist of:

Magnetic Core: Made from ferrite, powdered iron, or composite materials to concentrate magnetic flux
Coil Structure: Copper wire wound around the core (enamelled or silver-plated)
Encapsulation: Molded resin or ceramic coating for mechanical protection and insulation
Terminations: Solder-coated ends for PCB mounting (for SMD types) or leaded connections

4. Key Technical Specifications

Parameter	Description	Importance
Inductance (L)	Measured in henrys (H), determines energy storage capacity	Defines filtering/energy storage performance
Rated Current (I_rated)	Maximum DC current before saturation	Prevents core saturation and failure
DC Resistance (DCR)	Resistance of coil windings	Affects efficiency and thermal performance
Self-Resonant Frequency (SRF)	Frequency where inductor behaves as capacitor	Limits effective operating frequency range
Q Factor	Quality factor indicating efficiency	Higher Q = lower energy losses

5. Application Fields

Consumer Electronics: Smartphones, laptops, LED drivers
Industrial Equipment: Motor drives, power inverters
Automotive Systems: ECU modules, EV battery management
Telecom Infrastructure: Base station filters, optical transceivers

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Features
Murata	LQH3NPN100M	10 H, 1.2A, 1.8 1.4mm chip inductor
TDK	MLZ2012A100T	100MHz SRF, 1.0 1.25mm for RF circuits
Vishay	IHLP2525CZER1R0M	1 H, 12A, composite construction
Coilcraft	0402DC-103J	10 H, 5% tolerance, ultra-low profile

7. Selection Guidelines

Key considerations during selection:

Calculate required inductance based on switching frequency and ripple current
Verify rated current exceeds maximum operating current by 20-30%
Select SRF higher than circuit operating frequency
Consider package size vs. thermal dissipation requirements
For EMI suppression: Choose ferrite beads with impedance curves matching target frequencies

8. Industry Trends

Current development trends include:

Miniaturization: Sub-0.5mm size inductors for wearable devices
High-Frequency Operation: Components supporting >10GHz 5G applications
Integrated Solutions: Combined inductor-filter modules
Material Innovation: Nanocrystalline cores for higher saturation flux
Automotive Focus: AEC-Q qualified parts for EV/HEV systems