Fixed Inductors

Part Number	Description / PDF	Quantity
744760356A Würth Elektronik Midcom	FIXED IND 5.6UH 160MA 3 OHM SMD	1353
74479276168 Würth Elektronik Midcom	FIXED IND 680NH 2.5A 54 MOHM SMD	2425
744373340033 Würth Elektronik Midcom	FIXED IND 330NH 9A 7.3 MOHM SMD	0
78436432010 Würth Elektronik Midcom	FIXED IND 1UH 47A 0.6 MOHM SMD	48
744062001 Würth Elektronik Midcom	FIXED IND 1UH 4.8A 14 MOHM SMD	3830
744772022 Würth Elektronik Midcom	FIXED IND 2.2UH 6.7A 10 MOHM TH	650
744323220 Würth Elektronik Midcom	FIXED IND 2.2UH 9A 11.38 MOHM	1641
74436410680 Würth Elektronik Midcom	FIXED IND 6.8UH 36A 1.441 MOHM	40
744762333A Würth Elektronik Midcom	FIXED IND 3.3UH 185MA 2.85 OHM	0
7443630310 Würth Elektronik Midcom	FIXED IND 3.1UH 26A 2.09 MOHM	669
744761115A Würth Elektronik Midcom	FIXED IND 15NH 700MA 170MOHM SMD	3035
744325550 Würth Elektronik Midcom	FIXED IND 5.5UH 10A 10.3 MOHM	4193
744786233A Würth Elektronik Midcom	FIXED IND 330NH 150MA 2.8 OHM	4319
74404064101 Würth Elektronik Midcom	FIXED IND 100UH 800MA 433 MOHM	902
74402800047 Würth Elektronik Midcom	FIXED IND 470NH 2.5A 42 MOHM SMD	790
7447660068 Würth Elektronik Midcom	FIXED IND 680NH 450MA 600 MOHM	0
7447706330 Würth Elektronik Midcom	FIXED IND 33UH 3A 60MOHM SMD	1624
784773033 Würth Elektronik Midcom	FIXED IND 3.3UH 2A 86 MOHM SMD	0
7447231221 Würth Elektronik Midcom	FIXED IND 220UH 1.75A 200 MOHM	0
7447412331 Würth Elektronik Midcom	FIXED IND 330UH 500MA 2 OHM TH	140

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