Fixed Inductors

Part Number	Description / PDF	Quantity
B82482M1682M000 TDK EPCOS	PCM120T-6R8M-D; 12.4X13.1X11.5 M	0
B82470A1473M TDK EPCOS	FIXED IND 47UH 320MA 1.5 OHM SMD	0
B82141A1392K000 TDK EPCOS	FIXED IND 3.9UH 560MA 320 MOHM	0
B82496C3181J000 TDK EPCOS	FIXED IND 180NH 120MA 6 OHM SMD	17490
B78108E1681M009 TDK EPCOS	FIXED IND 680NH 4.6A 31 MOHM TH	177
B82422T1224K000 TDK EPCOS	FIXED IND 220UH 45MA 22 OHM SMD	5158
B82472D6223M000 TDK EPCOS	FIXED IND 22UH 1.65A 193 MOHM	0
B82442T1154K000 TDK EPCOS	FIXED IND 150UH 410MA 1.5 OHM	0
B82432C1224J000 TDK EPCOS	FIXED IND 220UH 115MA 7.5 OHM	0
B82477G2474M000 TDK EPCOS	FIXED IND 470UH 580MA 770 MOHM	424
B82562N4682N000 TDK EPCOS	FIXED IND 6.8UH 3.1A 27 MOHM SMD	0
B82477G4334M000 TDK EPCOS	FIXED IND 330UH 950MA 600 MOHM	1130
B82559A0951A013 TDK EPCOS	FIXED IND 950NH 25A 1.12 MOHM	2122
B82477D4153M000 TDK EPCOS	FIXED IND 15UH 3.25A 60 MOHM SMD	350
B82141A1473J000 TDK EPCOS	FIXED IND 47UH 200MA 2.4 OHM TH	816
B82442H1124J000 TDK EPCOS	FIXED IND 120UH 320MA 1.52 OHM	0
B78108S1104J000 TDK EPCOS	FIXED IND 100UH 370MA 1.7 OHM TH	0
B82141A1123K009 TDK EPCOS	FIXED IND 12UH 385MA 670 MOHM TH	0
B82559B7103A027 TDK EPCOS	FIXED IND 10UH 33A 1.92 MOHM SMD	140
B78108S1334J000 TDK EPCOS	FIXED IND 330UH 190MA 6.4 OHM TH	6501

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