Fixed Inductors

Part Number	Description / PDF	Quantity
B82422H1223K000 TDK EPCOS	FIXED IND 22UH 330MA 1 OHM SMD	17879
B82477P2105M000 TDK EPCOS	FIXED IND 1MH 530MA 1.3 OHM SMD	1133
B82477P4223M000 TDK EPCOS	FIXED IND 22UH 4.15A 35 MOHM SMD	272
B78108S1104J009 TDK EPCOS	FIXED IND 100UH 370MA 1.7 OHM TH	0
B82144B1336J000 TDK EPCOS	FIXED IND 33MH 35MA 150 OHM TH	0
B82422A3181J100 TDK EPCOS	FIXED IND 180NH 360MA 380 MOHM	0
B82422A3331K100 TDK EPCOS	FIXED IND 330NH 200MA 1.3 OHM	1326
B82442H1824K000 TDK EPCOS	FIXED IND 820UH 130MA 10.4 OHM	0
B82475A1224K000 TDK EPCOS	FIXED IND 220UH 660MA 730 MOHM	0
B82477G4333M000 TDK EPCOS	FIXED IND 33UH 3A 53 MOHM SMD	1883
B82498F3270J001 TDK EPCOS	FIXED IND 27NH 700MA 90 MOHM SMD	0
B82432T1333K000 TDK EPCOS	FIXED IND 33UH 400MA 1.2 OHM SMD	3164
B82472P6682M000 TDK EPCOS	FIXED IND 6.8UH 2.15A 42 MOHM	950
B82477R4202M100 TDK EPCOS	FIXED IND 2UH 9.5A 8 MOHM SMD	0
B82442T1152K000 TDK EPCOS	FIXED IND 1.5UH 3.02A 33 MOHM	0
B82422A3330J100 TDK EPCOS	FIXED IND 33NH 540MA 170 MOHM	0
B82477D4103M000 TDK EPCOS	FIXED IND 10UH 3.75A 42 MOHM SMD	271
B82472P6223M000 TDK EPCOS	FIXED IND 22UH 1.45A 91 MOHM SMD	935
B82422A3271J100 TDK EPCOS	FIXED IND 270NH 235MA 900 MOHM	0
B78148E1104J000 TDK EPCOS	FIXED IND 100UH 640MA 1.45 OHM	110

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