Fixed Inductors

Part Number	Description / PDF	Quantity
744045821 Würth Elektronik Midcom	FIXED IND 820UH 85MA 20 OHM SMD	468
7687714222 Würth Elektronik Midcom	FIXED IND 2.2MH 260MA 6.5 OHM	616
7443739650056 Würth Elektronik Midcom	FIXED IND 330NH 29.5A 0.8 MOHM	882
74404084010 Würth Elektronik Midcom	FIXED IND 1UH 6.3A 8 MOHM SMD	0
7441501 Würth Elektronik Midcom	FIXED IND 12UH 14.5A 8 MOHM TH	0
74455115 Würth Elektronik Midcom	FIXED IND 15UH 1.1A 230 MOHM SMD	0
110001101 Würth Elektronik Midcom	FIXED IND 10.4UH 2.5A 33 MOHM	1050
7443082018A Würth Elektronik Midcom	FIXED IND 180NH 65A 0.15MOHM SMD	733
744765118A Würth Elektronik Midcom	FIXED IND 18NH 420MA 230 MOHM	2316
7447669118 Würth Elektronik Midcom	FIXED IND 18UH 700MA 680 MOHM	85
7449152090 Würth Elektronik Midcom	FIXED IND 90NH 30A 1.21 MOHM SMD	327
784775139 Würth Elektronik Midcom	FIXED IND 39UH 1.25A 160 MOHM	0
744782015 Würth Elektronik Midcom	FIXED IND 1.5NH 300MA 180 MOHM	0
74404084680 Würth Elektronik Midcom	FIXED IND 68UH 1.25A 196 MOHM	1090
74457247 Würth Elektronik Midcom	FIXED IND 470UH 820MA 809 MOHM	182
7447480471 Würth Elektronik Midcom	FIXED IND 470UH 1.15A 520 MOHM	341
7447773680 Würth Elektronik Midcom	FIXED IND 68UH 1.15A 230 MOHM	412
744760182A Würth Elektronik Midcom	FIXED IND 82NH 500MA 320MOHM SMD	1800
7447773220 Würth Elektronik Midcom	FIXED IND 22UH 1.85A 87 MOHM SMD	1858
7443630140 Würth Elektronik Midcom	FIXED IND 1.4UH 31.5A 1.08 MOHM	190

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