Switching Converter, SMPS Transformers

Part Number	Description / PDF	Quantity
750316878 Würth Elektronik Midcom	OFFLINE TRANSFORMER EE16/7/5 THT	54
750316031 Würth Elektronik Midcom	PUSH-PULL TRANSFORMER WE-PP	211
750817015 Würth Elektronik Midcom	XFRMER FLYBACK AC/DC CONV SMD	0
750316670 Würth Elektronik Midcom	PUSH-PULL TRANSFORMER TOR5.8/3.1	1000
750315229 Würth Elektronik Midcom	PUSH-PULL TRANSFORMER	621
750317233 Würth Elektronik Midcom	FLYBACK TRANSFORMER EP7 SMT; UI	247
750315882 Würth Elektronik Midcom	FLYBACK TRANSFORMER WE-FB	463
750314459 Würth Elektronik Midcom	TRANSFORMER FLYBACK WE-FB SMD	0
7508116314 Würth Elektronik Midcom	OFFLINE TRANSFORMER WE-UNIT	36
750310471 Würth Elektronik Midcom	TRANS FLYBACK LT3573 25UH SMD	9
750313823 Würth Elektronik Midcom	WE-UNIT OFFLINE TRANSFORMER	0
750311439 Würth Elektronik Midcom	TRANS FLYBACK LT3748LT3575 37UH	0
750315422 Würth Elektronik Midcom	FLYBACK TRANSFORMER WE-FB	241
7508110160 Würth Elektronik Midcom	OFFLINE TRANSFORMER WE-UNIT	0
7491199501 Würth Elektronik Midcom	TRANS FLYBACK POE 127UH SMD	168
750310224 Würth Elektronik Midcom	POWER OVER ETHERNET UEBERTRAGER	0
750841630 Würth Elektronik Midcom	TRANS FLYBACK NXP UM10369 1.6MH	0
760895451 Würth Elektronik Midcom	WE-LLCR RESONANT CONVERTER 600UH	9
749196321 Würth Elektronik Midcom	TRANSFORMER 14.2UH .97A SMD	0
749196518 Würth Elektronik Midcom	WE-FLEX FLEXIBLE TRANSFORMER FOR	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.