Pulse Transformers

Part Number	Description / PDF	Quantity
PT61021EL J.W. Miller / Bourns	INDUCTOR RADIAL	0
SM453229-381N7Y J.W. Miller / Bourns	XFRMR LAN 10/100/1000 1:1 350UH	0
PT61020EL J.W. Miller / Bourns	PULSE XFMR 1CT:1 350UH	6075
SM91072AL-E J.W. Miller / Bourns	XFMR LAN 10/100 BASE-T 1:1 350UH	574
HCTSM80304BAL-E1 J.W. Miller / Bourns	XFRMR POWER 3:4 300UH SMD	393
SM353230-181N7Y J.W. Miller / Bourns	CHIP LAN XFMR,1 /2.5/5G,3.5X3.2X	2000
SM91071AL-E J.W. Miller / Bourns	XFRMR PULSE 10 BASE-T	2
SM91502ALE J.W. Miller / Bourns	BMS XFORMER 1-CH 1000V AECQ +125	3790
SM453230-121N7Y J.W. Miller / Bourns	CHIP LAN XFMR,1 /2.5/5/10G,4.7X3	2000
SM75056PEL J.W. Miller / Bourns	PULSE XFMR 1:1 TX 1:1 RX 1.2MH	0
PT61017PEL J.W. Miller / Bourns	PULSE XFMR 1CT:1CT 350UH	8893
PT61018AAPEL-S J.W. Miller / Bourns	PULSE XFMR 1CT:1CT 350UH	3827
HCTSM80910BAL-E1 J.W. Miller / Bourns	XFRMR POWER 9:10 300UH SMD	373
SM453230-181N7Y J.W. Miller / Bourns	CHIP LAN XFMR,1 /2.5/5G,4.7X3.2X	2000
SM91047EL J.W. Miller / Bourns	PULSE XFMR 11.875:1 5MH	1747
SM91074ALE J.W. Miller / Bourns	10/100 BASE T XFORMER AECQ +125	0
SM91073AL-E J.W. Miller / Bourns	XFRMR PULSE 10 BASE-T	600
SM51108PEL J.W. Miller / Bourns	PULSE XFMR 1CT:1CT 350UH	19
SM51430EL J.W. Miller / Bourns	TRANSFORMER G FAST 8SMD	0
HCTSM81017CAL-E1 J.W. Miller / Bourns	XFRMR POWER 10:17 350UH SMD	485

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