Fixed Inductors

Part Number	Description / PDF	Quantity
1537G Hammond Manufacturing	FIXED IND 30UH 8A 24 MOHM TH	64
1537J Hammond Manufacturing	FIXED IND 50UH 3.2A 64 MOHM TH	72
195E75 Hammond Manufacturing	FIXED IND 2.5MH 75A 8 MOHM CHASS	2
1539M17 Hammond Manufacturing	FIXED IND 1MH 2.5A 279 MOHM TH	0
1538M24 Hammond Manufacturing	FIXED IND 50UH 15A 13 MOHM TH	20
1540M02 Hammond Manufacturing	FIXED IND 25UH 5.5A 14 MOHM TH	9
1539M04 Hammond Manufacturing	FIXED IND 50UH 6.6A 34 MOHM TH	43
1540M07 Hammond Manufacturing	FIXED IND 75UH 5A 40 MOHM TH	5
1539M14 Hammond Manufacturing	FIXED IND 100UH 7A 34 MOHM TH	0
159T Hammond Manufacturing	FIXED IND 2.5H 300MA 43 OHM CHAS	1
195C75 Hammond Manufacturing	FIXED IND 1MH 75A 4 MOHM CHASSIS	0
1538M19 Hammond Manufacturing	FIXED IND 68UH 10A 23 MOHM TH	44
195J10 Hammond Manufacturing	FIXED IND 10MH 10A 70 MOHM CHASS	14
1537H Hammond Manufacturing	FIXED IND 40UH 5A 39 MOHM TH	25
1540M01 Hammond Manufacturing	FIXED IND 10UH 11A 8 MOHM TH	0
1536Y Hammond Manufacturing	FIXED IND 500UH 2A 260 MOHM TH	22
195C20 Hammond Manufacturing	FIXED IND 1MH 20A 13 MOHM CHASS	29
193L Hammond Manufacturing	FIXED IND 5H 300MA 57 OHM CHASS	0
195E30 Hammond Manufacturing	FIXED IND 2.5MH 30A 13 MOHM CHAS	21
1538M17 Hammond Manufacturing	FIXED IND 27UH 12.5A 14 MOHM TH	44

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