Fixed Inductors

Part Number	Description / PDF	Quantity
ECS-MPI4040R1-1R0-R ECS Inc. International	FIXED IND 1UH 3.7A 48 MOHM SMD	0
S1812R-271H API Delevan	FIXED IND 270NH 1.053A 180 MOHM	0
1812-391F API Delevan	FIXED IND 390NH 535MA 700 MOHM	0
MPX1D0840LR68 KEMET	FIXED IND 680NH 22.4A 3.6 MOHM	960
SRR0908-680ML J.W. Miller / Bourns	FIXED IND 68UH 1.25A 184MOHM SMD	0
CW160808-47NG J.W. Miller / Bourns	FIXED IND 47NH 600MA 280MOHM SMD	0
MGV2016102R2M-10 Laird - Performance Materials	FIXED IND 2.2UH 1.7A 150MOHM SMD	16687
BRL3225TR51M TAIYO YUDEN	FIXED IND 510NH 2.55A 37.7 MOHM	2130
0805CS-270EGTS Delta Electronics	FIXED IND 27NH 500MA 250 MOHM	3900
BRL3225T220K TAIYO YUDEN	FIXED IND 22UH 470MA 828 MOHM	114
1155EA-0001=P3 TOKO / Murata	FIXED IND 10UH 3A 25 MOHM SMD	1
HF1008-150M API Delevan	FIXED IND 15NH 1.053A 110 MOHM	0
LB2016T1R5M TAIYO YUDEN	FIXED IND 1.5UH 380MA 110 MOHM	0
CDPH4D19FNP-4R7MC Sumida Corporation	FIXED IND 4.7UH 3.3A 38 MOHM SMD	13716
IHLP2020CZER1R0M11 Vishay / Dale	FIXED IND 1UH 10A 11 MOHM SMD	0
SPM4015T-3R3M-LR TDK Corporation	FIXED IND 3.3UH 2.5A 116.6 MOHM	824
IMC1210BN82NM Vishay / Dale	FIXED IND 82NH 450MA 400 MOHM	0
LQG15WZ24NH02D TOKO / Murata	FIXED IND 24NH 230MA 1.2 OHM SMD	0
P1812-333H API Delevan	FIXED IND 33UH 300MA 1.578 OHM	0
744045821 Würth Elektronik Midcom	FIXED IND 820UH 85MA 20 OHM SMD	468

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