Fixed Inductors

Part Number	Description / PDF	Quantity
B82134A5151M000 TDK EPCOS	FIXED IND 420UH 150MA 19 OHM TH	0
B82442H1125K000 TDK EPCOS	FIXED IND 1.2MH 105MA 13.6 OHM	0
B82442T1335K050 TDK EPCOS	FIXED IND 3.3MH 85MA 32.8 OHM	0
B82482M1401N000 TDK EPCOS	PCM120T-R40N-D; 12.4X13.1X11.5 M	0
B82498F3820G000 TDK EPCOS	FIXED IND 82NH 500MA 190 MOHM	0
B82482M1681N000 TDK EPCOS	PCM120T-R82N-D; 12.4X13.1X11.5 M	0
B82475A1684K000 TDK EPCOS	FIXED IND 680UH 280MA 2.25 OHM	0
B82422T1682J000 TDK EPCOS	FIXED IND 6.8UH 180MA 1.8 OHM	0
B82559A3292A025 TDK EPCOS	FIXED INDUCTOR 2.9UH 1 MOHM SMD	0
B82442T1393K050 TDK EPCOS	FIXED IND 39UH 720MA 456 MOHM	0
B82442H1272K000 TDK EPCOS	FIXED IND 2.7UH 1.7A 56 MOHM SMD	0
B78108S1103K000 TDK EPCOS	FIXED IND 10UH 680MA 490 MOHM TH	5780
B78148E1151M009 TDK EPCOS	FIXED IND 150NH 6.5A 17 MOHM TH	0
B78148S1123K000 TDK EPCOS	FIXED IND 12UH 650MA 550 MOHM TH	0
B82559B4222A016 TDK EPCOS	FIXED IND 2.2UH 26.8A 1.8 MOHM	479
B82422T3390J000 TDK EPCOS	FIXED IND 39NH 450MA 190 MOHM	0
B82422A1222K100 TDK EPCOS	FIXED IND 2.2UH 270MA 750 MOHM	5437
B82144A2474J000 TDK EPCOS	FIXED IND 470UH 280MA 2.5 OHM TH	2184
B82477G4392M000 TDK EPCOS	FIXED IND 3.9UH 7.5A 12.5 MOHM	76
B82472P6472M000 TDK EPCOS	FIXED IND 4.7UH 2.5A 33 MOHM SMD	0

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