Fixed Inductors

Part Number	Description / PDF	Quantity
1538M06 Hammond Manufacturing	FIXED IND 150UH 4.6A 69 MOHM TH	28
194D Hammond Manufacturing	FIXED IND 5H 150MA 107.2 OHM	2
1536D Hammond Manufacturing	FIXED IND 3.35UH 20A 10 MOHM TH	38
1539M09 Hammond Manufacturing	FIXED IND 2.5MH 850MA 2.04 OHM	4
159M Hammond Manufacturing	FIXED IND 15H 100MA 256 OHM CHAS	9
159ZA Hammond Manufacturing	FIXED IND 300MH 1A 6 OHM CHASSIS	40
1539M05 Hammond Manufacturing	FIXED IND 100UH 4.5A 72 MOHM TH	54
1538M01 Hammond Manufacturing	FIXED IND 5UH 10A 13 MOHM TH	98
153E Hammond Manufacturing	FIXED IND 7H 25MA 770 OHM CHASS	7
1539M01 Hammond Manufacturing	FIXED IND 5UH 15A 7 MOHM TH	2
193M Hammond Manufacturing	FIXED IND 10H 300MA 63 OHM CHASS	4
156R Hammond Manufacturing	FIXED IND 1.5H 200MA 56 OHM CHAS	49
1538M09 Hammond Manufacturing	FIXED IND 10UH 12A 12 MOHM TH	68
1539M21 Hammond Manufacturing	FIXED IND 250UH 6.4A 59 MOHM TH	28
1539M31 Hammond Manufacturing	FIXED IND 5MH 2.2A 714 MOHM TH	22
1538M07 Hammond Manufacturing	FIXED IND 250UH 4A 89 MOHM TH	49
1532E Hammond Manufacturing	FIXED IND 55UH 500MA 1 OHM TH	461
195E20 Hammond Manufacturing	FIXED IND 2.5MH 20A 22 MOHM CHAS	42
1537K Hammond Manufacturing	FIXED IND 75UH 2A 128 MOHM TH	85
1539M28 Hammond Manufacturing	FIXED IND 500UH 6.5A 85 MOHM TH	4

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