Fixed Inductors

Part Number	Description / PDF	Quantity
VLF252012MT-1R5N-CA TDK Corporation	FIXED IND 1.5UH 2.17A 69 MOHM	0
DRA127-331-R PowerStor (Eaton)	FIXED IND 330UH 1.011A 612 MOHM	335
SDET25201T-1R5MS Delta Electronics	FIXED IND 1.5UH 1.7A 114MOHM SMD	4900
LQH32PB680MN0L TOKO / Murata	FIXED IND 68UH 275MA 2.74 OHM	0
LQP03TN22NH02D TOKO / Murata	FIXED IND 22NH 150MA 1.9 OHM SMD	29750
SRP0412-100K J.W. Miller / Bourns	FIXED IND 10UH 1.7A 250 MOHM SMD	4300
AISC-1008-R75J-T Abracon	FIXED IND 750NH 360MA 1.54 OHM	1653
1537R Hammond Manufacturing	FIXED IND 1MH 1.25A 830 MOHM TH	11
CML0306-6N8-JNH Delta Electronics	FIXED IND 6.8NH 230MA 700 MOHM	0
MPXV1D1770L4R7 KEMET	FIXED IND 4.7UH 23.5A 4.8 MOHM	0
MLF2012K560KT000 TDK Corporation	FIXED IND 56UH 4MA 2.8 OHM SMD	5555
SRR0805-271K J.W. Miller / Bourns	FIXED IND 270UH 270MA 1.4OHM SMD	0
1235AS-H-6R8M=P3 TOKO / Murata	FIXED IND 6.8UH 1.9A 106 MOHM	1946
IHSM7832ER470L Vishay / Dale	FIXED IND 47UH 2.6A 120 MOHM SMD	0
HCPT1309-2R2-R PowerStor (Eaton)	FIXED IND 2.27UH 12.5A 4.1 MOHM	0
IMC1210ER27NK Vishay / Dale	FIXED IND 27NH 564MA 220 MOHM	0
MHQ1005P22NGTD25 TDK Corporation	FIXED IND 22NH 230MA 1.1 OHM SMD	20000
CBC2012T100M TAIYO YUDEN	FIXED IND 10UH 340MA 1.56 OHM	10159
B82442H1824K000 TDK EPCOS	FIXED IND 820UH 130MA 10.4 OHM	0
XPL2010-103MLC COILCRAFT	SHIELDED POWER INDUCTORS, 10UH	11606

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