Arrays, Signal Transformers

Part Number	Description / PDF	Quantity
SRF1260-221M J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 220UH SMD	1105
SRF1280-681M J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 680UH SMD	0
PM3604-250-RC J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 250UH SMD	0
SRF1260-100M J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 10UH SMD	0
PM3602-300-RC J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 300UH SMD	6550
SRF1280-R47Y J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 470NH SMD	30
SRF1280A-2R2Y J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 2.2UH SMD	0
SRF1260A-330M J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 33UH SMD	1600
SRF1280-330M J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 33UH SMD	251
SRF1260-821M J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 820UH SMD	0
SRF1280A-820M J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 82UH SMD	59
PM3604-25-RC J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 25UH SMD	399
SRF0703-4R7M J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 4.7UH SMD	9151
PM3604-68-RC J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 68UH SMD	425
SRF1280A-330M J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 33UH SMD	187
SRF1280A-1R0Y J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 1UH SMD	1567
SRF1280-470M J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 47UH SMD	799
SRF1280A-151M J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 150UH SMD	106
SRF1280A-6R8Y J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 6.8UH SMD	391
PM3604-100-RC J.W. Miller / Bourns	INDUCT ARRAY 2 COIL 100UH SMD	370

Arrays, Signal Transformers

1. Overview

Inductors, coils, chokes, arrays, and signal transformers are fundamental passive components in electronic systems. Inductors store energy in magnetic fields, chokes suppress high-frequency noise, arrays integrate multiple magnetic elements, and signal transformers enable voltage conversion and galvanic isolation. These components are critical in power management, signal processing, electromagnetic interference (EMI) mitigation, and communication systems. Their advancements drive miniaturization, efficiency, and performance in modern electronics.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
Wire-wound Inductors	High inductance values, low DC resistance	Switching power supplies
Ferrite Bead Chokes	High impedance at high frequencies	EMI filtering in USB interfaces
Common-mode Choke Arrays	Suppress differential and common-mode noise	Industrial motor drives
Signal Transformers	Galvanic isolation, voltage scaling	Telecom network interfaces
Thin-film Inductor Arrays	Ultra-low profile, tight coupling	RF front-end modules

3. Structure and Composition

Typical structures include:

Inductors: Wound conductive wire (copper/enamelled aluminum) on magnetic cores (ferrite, powdered iron)
Chokes: Toroidal or drum cores with single/dual windings
Arrays: Monolithic integration of multiple chokes/inductors in single package
Signal Transformers: Primary/secondary coils with electrostatic shielding, E-I or toroidal cores

4. Key Technical Specifications

Parameter	Description	Importance
Inductance (L)	Defines energy storage capacity ( H-mH range)	Determines filtering performance
Rated Current	Max DC/AC current before saturation	Prevents core saturation in power circuits
DCR	DC resistance of windings	Affects power efficiency
Self-resonant Frequency	Frequency where parasitic capacitance dominates	Limits usable frequency range
Turns Ratio	Primary/secondary winding ratio	Defines voltage transformation ratio

5. Application Fields

Key industries:

Telecommunications: Base station power systems, optical transceivers
Consumer Electronics: Mobile chargers, LED drivers
Automotive: EV battery management systems, ADAS sensors
Industrial: Programmable logic controllers (PLCs), inverters

6. Leading Manufacturers and Products

Manufacturer	Representative Products	Key Features
TDK	INDUCTOR,Wire-wound: VLS6045EX	6.0 4.5 4.5mm, 120A rated current
Coilcraft	Common-mode Choke: 114008	1.8kV isolation, 100MHz bandwidth
Bourns	Signal Transformer: SM4112	1:1:1:1 ratio, 1500V isolation
Pulse Electronics	LAN Transformer: HX4008NL	Integrated magnetics for Gigabit Ethernet
Sumida	Power Choke: CDRH3D28	3.3 H-100 H, 125A peak current

7. Selection Guidelines

Consider:

Inductance value and tolerance ( 20% typical for power chokes)
Operating frequency vs. self-resonant frequency
Thermal management (temperature rise 40 C)
Package size (0402-2200 for surface-mount devices)
Isolation voltage ( 1.5kV for industrial applications)

8. Industry Trends

Emerging trends:

Miniaturization: 01005-sized inductors for wearable devices
High-frequency operation: Multi-GHz transformers for 5G infrastructure
Integrated magnetics: Combined inductors/transformers in SiP solutions
Advanced materials: Amorphous/nanocrystalline cores for high-efficiency EV chargers
Automotive-grade reliability: AEC-Q200 qualified components for e-mobility