Pulse Transformers

Part Number	Description / PDF	Quantity
SM51589PEL J.W. Miller / Bourns	PULSE XFMR 1CT:1CT 350UH	17
SM91501ALE J.W. Miller / Bourns	BMS XFORMER 2-CH 1600V AECQ +125	2591
SM13072APEL J.W. Miller / Bourns	LAN 10/100 BASE T XFORMER AECQ +	470
SM41126EL J.W. Miller / Bourns	CHIP LAN XFMR MODULE,10/100 TX,W	24
SM91509AL-E J.W. Miller / Bourns	XFRMR PULSE 1:1 600UH SMD	4400
PT61018PEL J.W. Miller / Bourns	PULSE XFMR 1CT:1CT 350UH	4217
HCTSM80102AAL-E1 J.W. Miller / Bourns	XFRMR POWER 1:2 250UH SMD	372
SM453229-231N7Y J.W. Miller / Bourns	CHIP LAN,10/100/1G XFORMER,POE,4	0
SM75057PEL J.W. Miller / Bourns	PULSE XFMR 1:2 TX 1:2 RX 1.2MH	0
SM91508AL-E J.W. Miller / Bourns	XFRMR PULSE 1:1 300UH SMD	706
SM51625EL J.W. Miller / Bourns	XFRMR LAN POE+ 1.2A 24SMD	5673
SM43P01EL J.W. Miller / Bourns	LAN TRANSFORMER	800
PT61022XEL J.W. Miller / Bourns	PULSE XFMR 1CT:1CT 350UH	1245
SM43001EL J.W. Miller / Bourns	LAN TRANSFORMER	800
SM42002EL J.W. Miller / Bourns	LAN TRANSFORMER	800
SM42P01EL J.W. Miller / Bourns	LAN TRANSFORMER	800
SM13100EL J.W. Miller / Bourns	LAN 10/100 BASE T XFORMER 250VRM	546
SM13126PEL J.W. Miller / Bourns	10/100 BASE TX LAN POE +85 C, IE	23
PT61018AAPEL J.W. Miller / Bourns	LAN 10/100 BASE T XFORMER AECQ +	0
PT60011L J.W. Miller / Bourns	INDUCTOR RADIAL	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