Fixed Inductors

Part Number	Description / PDF	Quantity
B78148S1105J009 TDK EPCOS	FIXED IND 1MH 130MA 14 OHM TH	0
B82442H1104K000 TDK EPCOS	FIXED IND 100UH 350MA 1.28 OHM	14
B82462G4222M000 TDK EPCOS	FIXED IND 2.2UH 2.55A 25 MOHM	19781
B82477G2123M000 TDK EPCOS	FIXED IND 12UH 3.5A 27 MOHM SMD	0
B82144F2222K000 TDK EPCOS	FIXED IND 2.2UH 3.65A 55 MOHM TH	1189
B82559B2102A027 TDK EPCOS	FIXED IND 1UH 52A 0.46 MOHM SMD	283
B82498F3100G000 TDK EPCOS	FIXED IND 10NH 700MA 90 MOHM SMD	0
B82422T1683K000 TDK EPCOS	FIXED IND 68UH 60MA 9 OHM SMD	2487
B78148S1184J009 TDK EPCOS	FIXED IND 180UH 270MA 3 OHM TH	0
B82442H1273K000 TDK EPCOS	FIXED IND 27UH 620MA 420 MOHM	3452
B82141A1122K000 TDK EPCOS	FIXED IND 2.2UH 700MA 200 MOHM	0
B82432T1274K000 TDK EPCOS	FIXED IND 270UH 120MA 10.5 OHM	4699
B82422H1474J000 TDK EPCOS	FIXED IND 470UH 76MA 20 OHM SMD	4269
B82422T1104K000 TDK EPCOS	FIXED IND 100UH 60MA 11 OHM SMD	5800
B82422H1153J000 TDK EPCOS	FIXED IND 15UH 390MA 720 MOHM	0
B82144B1106J000 TDK EPCOS	FIXED IND 10MH 85MA 42 OHM TH	0
B82442H1335J000 TDK EPCOS	FIXED IND 3.3MH 55MA 48 OHM SMD	0
B78108S1225K000 TDK EPCOS	FIXED IND 2.2MH 80MA 34.7 OHM TH	0
B82464G4684M000 TDK EPCOS	FIXED IND 680UH 420MA 1.3 OHM	964
B82477D4302M900 TDK EPCOS	FIXED IND 3UH 5.84A 22 MOHM SMD	700

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