Switching Converter, SMPS Transformers

Part Number	Description / PDF	Quantity
750315834 Würth Elektronik Midcom	FLYBACK TRANSFORMER WE-FB	0
750311402 Würth Elektronik Midcom	TRANS FLYBACK NXPSSL2101 SSL2102	0
7491194501 Würth Elektronik Midcom	TRANS FLYBACK POE+ 42UH SMD	5
750313460 Würth Elektronik Midcom	TRANS FLYBACK LT8302	250
7491181012 Würth Elektronik Midcom	TRANSFORMER OFF LINE 4000V	40
749196548 Würth Elektronik Midcom	WE-FLEX FLEXIBLE TRANSFORMER FOR	0
749196517 Würth Elektronik Midcom	WE-FLEX FLEXIBLE TRANSFORMER FOR	0
750370042 Würth Elektronik Midcom	TRANS FLYBACK LT3573 15UH SMD	0
750813134 Würth Elektronik Midcom	TRANSFORMER FLYBACK LT3799	958
750341137 Würth Elektronik Midcom	TRANSFORMER PLANAR 480UH SMD	0
750341379 Würth Elektronik Midcom	POWER TRANSFORMER ADI ADP1051	77
750310346 Würth Elektronik Midcom	POWER OVER ETHERNET UEBERTRAGER	0
760871142 Würth Elektronik Midcom	TRANSFORMER OFFLINE 1.25MH 4000V	252
750032395 Würth Elektronik Midcom	POWER OVER ETHERNET TRANSFORMER	0
7508170310 Würth Elektronik Midcom	XFRMER FLYBACK AC/DC CONV SMD	171
7508112515 Würth Elektronik Midcom	OFFLINE TRANSFORMER WE-UNIT	0
7491195212 Würth Elektronik Midcom	TRANS FLYBACK POE SMD	58
750311596 Würth Elektronik Midcom	TRANS FLYBACK LT3748 12UH SMD	135
7508111323 Würth Elektronik Midcom	OFFLINE TRANSFORMER 12W EE16/8/5	150
750341142 Würth Elektronik Midcom	TRANSFORMER PLANAR 70UH SMD	0

Switching Converter, SMPS Transformers

1. Overview

Switching Mode Power Supply (SMPS) Transformers are critical components in power electronics systems, enabling efficient voltage conversion through high-frequency switching techniques. Unlike traditional linear transformers, SMPS transformers operate at frequencies typically above 20 kHz, allowing reduced size, weight, and improved energy efficiency. These components are essential for modern power management solutions in electronics, renewable energy systems, and industrial automation.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
Discontinuous Mode (DCM) Flyback	Galvanic isolation, single-switch control	AC-DC adapters, battery chargers
Continuous Mode (CCM) Flyback	Higher power density, lower ripple current	LED drivers, industrial power supplies
Forward Converter	Efficient for medium power levels, requires reset circuit	Server power supplies, telecom equipment
Push-Pull	Balanced magnetic utilization, high efficiency	High-end audio amplifiers, welding machines
Half-Bridge/Full-Bridge	High power capability, symmetrical switching	Electric vehicle charging, solar inverters

3. Structure and Components

Typical SMPS transformer construction includes:

Core materials: Ferrite (Mn-Zn or Ni-Zn), Powdered Iron, Amorphous alloys
Winding configuration: Primary/secondary windings with optimized turn ratios
Insulation system: Bobbins, tape insulation, and potting compounds
Termination: Tin-plated copper leads or surface-mount pads
Shielding: Electrostatic shields for EMI reduction

4. Key Technical Specifications

Parameter	Importance
Input Voltage Range	Determines compatibility with power sources
Output Power Rating	Defines maximum energy transfer capability
Switching Frequency	Impacts size, efficiency, and EMI performance
Turns Ratio Accuracy	Affects voltage regulation precision
Isolation Voltage	Ensures safety and dielectric strength
Efficiency (Typical >90%)	Reduces thermal management requirements
Operating Temperature	Determines reliability in harsh environments

5. Application Fields

Major application sectors include:

Consumer Electronics: Mobile device chargers, laptop adapters
Industrial: Motor drives, PLC power supplies, test equipment
Telecommunications: Base station power systems, optical network equipment
Renewable Energy: Solar inverters, energy storage systems
Automotive: On-board chargers (OBC), DC-DC converters
Medical: Isolated power supplies for diagnostic equipment

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Features
TDK-Lambda	PWM Switching Transformer	High-density design, 150kHz operating frequency
Coilcraft	XEL60xx Series	Ultra-low profile, 25A saturation current
Pulse Electronics	PA5477NL	Integrated EMI filtering, automotive qualified
Bel/Signal Transformer	125-2011-F	Medical-grade isolation, 4kV withstand
Delta Electronics	TMA-101-01	High-efficiency (94%), 1kW power rating

7. Selection Guidelines

Key considerations for optimal selection:

Power requirements (continuous vs peak load)
Switching frequency compatibility with controller ICs
Thermal management capabilities
Creepage/clearance distances for safety certification
Cost-performance trade-offs
Package dimensions and mounting requirements
Compliance with standards (UL, IEC, AEC-Q)

8. Industry Trends

Current development directions include:

Miniaturization through higher operating frequencies (>1MHz)
Integration with wide-bandgap semiconductors (GaN/SiC)
Advanced nanocrystalline core materials
AEC-Q qualified components for automotive electrification
Smart transformers with embedded sensing
RoHS-compliant, halogen-free construction

Market forecasts indicate 8.2% CAGR through 2028, driven by 5G infrastructure and renewable energy adoption.