Fixed Inductors

Part Number	Description / PDF	Quantity
L-07WR12KV4T Johanson Technology	FIXED IND 120NH 100MA 2.66 OHM	0
L-05B1N8SV6T Johanson Technology	FIXED IND 1.8NH 300MA 220 MOHM	0
L-14W27NGV4E Johanson Technology	FIXED IND 27NH 600MA 220 MOHM	0
L-07C82NJV6T Johanson Technology	FIXED IND 82NH 100MA 2.5 OHM SMD	0
L-07W9N0JV4T Johanson Technology	FIXED IND 9NH 680MA 104 MOHM SMD	0
L-15WR27JV4E Johanson Technology	FIXED IND 270NH 350MA 1.46 OHM	0
L-14C56NJV4T Johanson Technology	FIXED IND 56NH 300MA 1.1 OHM SMD	31522
L-07W13NKV4T Johanson Technology	FIXED IND 13NH 560MA 210 MOHM	0
L-07W27NKV4T Johanson Technology	FIXED IND 27NH 400MA 298 MOHM	0
L-07W11NKV4T Johanson Technology	FIXED IND 11NH 640MA 120 MOHM	0
L-05B3N9SV6T Johanson Technology	FIXED IND 3.9NH 300MA 450 MOHM	515
L-14W2N0CV4E Johanson Technology	FIXED IND 2NH 700MA 80 MOHM SMD	3525
L-07W39NGV4T Johanson Technology	FIXED IND 39NH 320MA 550 MOHM	0
L-07C43NJV6T Johanson Technology	FIXED IND 43NH 150MA 1.3 OHM SMD	0
L-07W12NGV4T Johanson Technology	FIXED IND 12NH 640MA 120 MOHM	0
L-07C4N3SV6T Johanson Technology	FIXED IND 4.3NH 300MA 240 MOHM	160579
L-07C18NJV6T Johanson Technology	FIXED IND 18NH 200MA 650 MOHM	0
L-05B15NJV6T Johanson Technology	FIXED IND 15NH 250MA 1.4 OHM SMD	9778
L-07W3N3JV4T Johanson Technology	FIXED IND 3.3NH 840MA 66 MOHM	0
L-05B22NJV6T Johanson Technology	FIXED IND 22NH 200MA 1.8 OHM SMD	8574

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