Fixed Inductors

Part Number	Description / PDF	Quantity
L-07W27NJV4T Johanson Technology	FIXED IND 27NH 400MA 298 MOHM	0
L-07C2N0SV6T Johanson Technology	FIXED IND 2NH 300MA 160 MOHM SMD	0
L-07W39NKV4T Johanson Technology	FIXED IND 39NH 320MA 550 MOHM	0
L-14C4N7KV4T Johanson Technology	FIXED IND 4.7NH 300MA 300 MOHM	0
L-14W1N8CV4E Johanson Technology	FIXED IND 1.8NH 700MA 80 MOHM	0
L-14W8N2KV4E Johanson Technology	FIXED IND 8.2NH 700MA 100 MOHM	0
L-15WR22GV4E Johanson Technology	FIXED IND 220NH 400MA 1 OHM SMD	0
L-05B39NKV6T Johanson Technology	FIXED IND 39NH 200MA 2.5 OHM SMD	0
L-15W22NJV4E Johanson Technology	FIXED IND 22NH 600MA 100 MOHM	0
L-05B1N0SV6T Johanson Technology	FIXED IND 1NH 300MA 120 MOHM SMD	4872
L-05B3N3SV6T Johanson Technology	FIXED IND 3.3NH 300MA 380 MOHM	25037
L-05B20NJV6T Johanson Technology	FIXED IND 20NH 200MA SMD	0
L-05B3N0SV6T Johanson Technology	FIXED IND 3NH 300MA 360 MOHM SMD	0
L-14WR12GV4E Johanson Technology	FIXED IND 120NH 300MA 650 MOHM	0
L-07W19NKV4T Johanson Technology	FIXED IND 19NH 480MA 202 MOHM	0
L-05B8N2KV6T Johanson Technology	FIXED IND 8.2NH 250MA 900 MOHM	0
L-07W27NGV4T Johanson Technology	FIXED IND 27NH 400MA 298 MOHM	0
L-15W47NKV4E Johanson Technology	FIXED IND 47NH 500MA 150 MOHM	0
L-07C82NKV6T Johanson Technology	FIXED IND 82NH 100MA 2.5 OHM SMD	0
L-15F3R3KV4E Johanson Technology	FIXED IND 3.3UH 210MA 2.3 OHM	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