Pulse Transformers

Part Number	Description / PDF	Quantity
S558-5500-JV Bel Fuse, Inc.	XFRMR LAN 5G 60W POE SMD	380
S553-5999-86-F Bel Fuse, Inc.	MODULE XFRMR LAN 10B-T SMD	0
S558-5999-J1-F Bel Fuse, Inc.	MODULE XFRMR LAN 10/100B-TX SMD	300
S558-5500-25-F Bel Fuse, Inc.	MODULE XFRMR LAN 10/100 POE SMD	865
S558-5999-46-F Bel Fuse, Inc.	MODULE XFRMR LAN 10/100B-TX SMD	794
S558-10GB-23 Bel Fuse, Inc.	MODULE XFRMR LAN 10G POE SMD	300
S558-5999-AC-F Bel Fuse, Inc.	MODULE XFRMR LAN GIGABIT 24P SMD	634
S558-5999-AF-F Bel Fuse, Inc.	MODULE XFRMR LAN 10/100B-TX SMD	0
S558-5999-M8-F Bel Fuse, Inc.	MODULE XFRMR LAN GIGABIT 24P SMD	0
S558-5999-Z5-F Bel Fuse, Inc.	MODULE XFRMR LAN 10/100B-TX SMD	4813
S553-0013-01-F Bel Fuse, Inc.	XFRMR MODULE LAN T1/CEPT DUAL	0
S553-6500-44-F Bel Fuse, Inc.	PULSE XFMR 1:1.15/1:1 1.2MH	0
S554-6500-21-F Bel Fuse, Inc.	MODULE XFRMR	0
S558-5500-44 Bel Fuse, Inc.	TRANSFORMER PULSE	0
S558-10GB-10 Bel Fuse, Inc.	TRANSFORMER PULSE	0
S560-6600-JA-F Bel Fuse, Inc.	MODULE XFRMR	0
S554-6500-25-F Bel Fuse, Inc.	PULSE XFMR 1:1 40UH 60UH 80UH	0
S558-10GB-05 Bel Fuse, Inc.	TRANSFORMER PULSE	0
S553-5999-D6-F Bel Fuse, Inc.	PULSE TRANSFORMER 85UH	0
S560-6600-HW-F Bel Fuse, Inc.	MODULE XFRMR	0

Pulse Transformers

1. Overview

Pulse transformers are specialized electromagnetic devices designed to transfer electrical pulse signals between circuits while maintaining galvanic isolation. They play a critical role in modern electronics by enabling efficient signal transmission, voltage level conversion, and noise suppression. Their unique ability to handle fast transient signals makes them essential in power electronics, telecommunications, and industrial control systems.

2. Main Types and Functional Classification

Type	Functional Features	Application Examples
Signal Pulse Transformer	High bandwidth, fast rise time (ns level), low distortion	Digital communication interfaces (RS485, Ethernet)
Power Pulse Transformer	High voltage isolation (>1kV), high efficiency (>90%)	Switch-mode power supplies (SMPS), motor drives
High-Voltage Pulse Transformer	Multi-kV insulation, partial discharge resistance	X-ray generators, radar systems
Wideband Pulse Transformer	Frequency range: 100kHz-100MHz, flat response curve	RF amplifiers, test equipment

3. Structure and Components

Typical construction includes:

Primary/secondary windings: Enamelled copper wire with precise turn ratio
Magnetic core: Ferrite (high permeability), powdered iron (high saturation)
Insulation system: Multi-layer dielectric barriers, vacuum pressure impregnation
Termination: Surface-mount pads or through-hole pins

Advanced designs use planar transformers with PCB-integrated windings for improved thermal management.

4. Key Technical Parameters

Parameter	Typical Range	Importance
Turns Ratio	1:1 to 1:100	Voltage scaling accuracy
Frequency Range	100kHz-10MHz	Signal integrity maintenance
Isolation Voltage	500V-30kV	Safety compliance (UL/IEC)
Pulse Rise Time	1ns-50ns	Digital signal fidelity
Leakage Inductance	<1 H	Efficiency optimization

5. Application Fields

Power Electronics: Isolated gate drivers for IGBT/MOSFET
Telecommunications: DSL line interface units
Medical Equipment: Patient-isolated monitoring systems
Industrial Control: PLC signal transmission
Automotive: EV battery management system (BMS) isolation

Case Study: In electric vehicle chargers, pulse transformers enable 1500V isolation between grid and battery systems while maintaining 98% signal integrity at 2MHz switching frequency.

6. Leading Manufacturers

Manufacturer	Key Product Series	Specifications
Coilcraft	Pulse-Hi Series	1:1.4 ratio, 25kV isolation, 100MHz bandwidth
Pulse Electronics	PA1538NL	1:16 ratio, 3kV isolation, 100ns rise time
TDK-Lambda	CUT100	2.5kV isolation, 2MHz frequency, SMD package

7. Selection Guidelines

Key considerations:

Match turns ratio with driver/receiver voltage requirements
Verify insulation class against system safety standards
Check frequency response vs. signal bandwidth requirements
Consider thermal rating for continuous power operation
Evaluate PCB footprint constraints (through-hole vs SMD)

8. Industry Trends

Current development directions include:

Miniaturization through nanocrystalline core materials
Integration with EMI filtering components
Increased operating frequencies (>10MHz) for 5G infrastructure
SiC/GaN compatible designs for wide bandgap power devices
Automotive-grade models for 800V EV systems