Fixed Inductors

Part Number	Description / PDF	Quantity
L-14CR15KV4T Johanson Technology	FIXED IND 150NH 300MA 2.4 OHM	0
L-14CR12KV4T Johanson Technology	FIXED IND 120NH 300MA 2.3 OHM	0
L-15W3N3SV4E Johanson Technology	FIXED IND 3.3NH 800MA 80 MOHM	0
L-07W23NKV4T Johanson Technology	FIXED IND 23NH 400MA 214 MOHM	0
L-15WR18JV4E Johanson Technology	FIXED IND 180NH 400MA 780 MOHM	0
L-14W22NKV4E Johanson Technology	FIXED IND 22NH 700MA 220 MOHM	0
L-14CR18KV4T Johanson Technology	FIXED IND 180NH 300MA 2.7 OHM	0
L-14C47NKV4T Johanson Technology	FIXED IND 47NH 300MA 1 OHM SMD	0
L-07W12NJV4T Johanson Technology	FIXED IND 12NH 640MA 120 MOHM	0
L-14C82NJV4T Johanson Technology	FIXED IND 82NH 300MA 1.8 OHM SMD	1070
L-07C8N2KV6T Johanson Technology	FIXED IND 8.2NH 250MA 400 MOHM	0
L-07C68NJV6T Johanson Technology	FIXED IND 68NH 100MA 2.2 OHM SMD	0
L-07W11NJV4T Johanson Technology	FIXED IND 11NH 640MA 120 MOHM	0
L-07W2N7CV4T Johanson Technology	FIXED IND 2.7NH 640MA 120 MOHM	0
L-07WR12JV4T Johanson Technology	FIXED IND 120NH 100MA 2.66 OHM	0
L-07C3N9KV6T Johanson Technology	FIXED IND 3.9NH 300MA 220 MOHM	0
L-05B5N6KV6T Johanson Technology	FIXED IND 5.6NH 300MA 600 MOHM	0
L-07W19NJV4T Johanson Technology	FIXED IND 19NH 480MA 202 MOHM	0
L-05B5N1SV6T Johanson Technology	FIXED IND 5.1NH 300MA 550 MOHM	0
L-15WR18GV4E Johanson Technology	FIXED IND 180NH 400MA 780 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