Fixed Inductors

Part Number	Description / PDF	Quantity
L-15FR47JV4E Johanson Technology	FIXED IND 470NH 500MA 950 MOHM	0
L-07C12NKV6T Johanson Technology	FIXED IND 12NH 250MA 500 MOHM	0
L-15W6N8JV4E Johanson Technology	FIXED IND 6.8NH 600MA 60 MOHM	0
L-15WR12JV4E Johanson Technology	FIXED IND 120NH 500MA 480 MOHM	0
L-15WR33KV4E Johanson Technology	FIXED IND 330NH 300MA 1.65 OHM	0
L-05B4N7SV6T Johanson Technology	FIXED IND 4.7NH 300MA 500 MOHM	0
L-07W9N5KV4T Johanson Technology	FIXED IND 9.5NH 680MA 200 MOHM	0
L-14W7N5KV4E Johanson Technology	FIXED IND 7.5NH 700MA 110 MOHM	0
L-14C39NKV4T Johanson Technology	FIXED IND 39NH 300MA 850 MOHM	0
L-07C6N2KV6T Johanson Technology	FIXED IND 6.2NH 300MA 300 MOHM	0
L-07C3N6KV6T Johanson Technology	FIXED IND 3.6NH 300MA 210 MOHM	0
L-05B12NJV6T Johanson Technology	FIXED IND 12NH 250MA 1.3 OHM SMD	6712
L-15WR22KV4E Johanson Technology	FIXED IND 220NH 400MA 1 OHM SMD	0
L-15FR68KV4E Johanson Technology	FIXED IND 680NH 400MA 1.2 OHM	0
L-14W5N6KV4E Johanson Technology	FIXED IND 5.6NH 700MA 110 MOHM	0
L-14W56NJV4E Johanson Technology	FIXED IND 56NH 600MA 310 MOHM	0
L-14C5N6KV4T Johanson Technology	FIXED IND 5.6NH 300MA 300 MOHM	0
L-15W39NJV4E Johanson Technology	FIXED IND 39NH 500MA 180 MOHM	0
L-14WR15KV4E Johanson Technology	FIXED IND 150NH 280MA 920 MOHM	0
L-07C3N9SV6T Johanson Technology	FIXED IND 3.9NH 300MA 220 MOHM	468920

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