TVS - Thyristors

Image	Part Number	Description / PDF	Quantity	Rfq
	NP3100SDMCT3G Sanyo Semiconductor/ON Semiconductor	THYRISTOR 275V 200A DO214AA	0
	NTVB200SC-L Sanyo Semiconductor/ON Semiconductor	THYRISTOR 200V 100A DO214AA	0
	NP0900SBMCT3G Sanyo Semiconductor/ON Semiconductor	THYRISTOR 75V 250A DO214AA	0
	MMT05A260T3G Sanyo Semiconductor/ON Semiconductor	THYRISTOR 200V 150A DO214AC	0
	NTVB170SC-L Sanyo Semiconductor/ON Semiconductor	THYRISTOR 170V 100A DO214AA	0
	NTVB300SA-L Sanyo Semiconductor/ON Semiconductor	THYRISTOR 300V 50A DO214AA	0
	NTVB058NSC-L Sanyo Semiconductor/ON Semiconductor	THYRISTOR 58V 100A DO214AA	0
	NP0900SCT3G Sanyo Semiconductor/ON Semiconductor	THYRISTOR 75V 100A DO214AA	0
	NP1500SBMCT3G Sanyo Semiconductor/ON Semiconductor	THYRISTOR 140V 250A DO214AA	0
	NP3100SCT3G Sanyo Semiconductor/ON Semiconductor	THYRISTOR 275V 100A DO214AA	0
	NP0900SCMCT3G Sanyo Semiconductor/ON Semiconductor	THYRISTOR 75V 400A DO214AA	0

TVS - Thyristors

1. Overview

Transient Voltage Suppression (TVS) diodes and Thyristors are critical components in circuit protection systems. TVS diodes are semiconductor devices designed to protect sensitive electronics from voltage spikes caused by electrostatic discharge (ESD), inductive load switching, or lightning strikes. Thyristors, a family of semiconductor devices including Silicon-Controlled Rectifiers (SCRs) and Triacs, are used for high-power switching and overvoltage protection. Both technologies are essential in modern electronics, ensuring reliability in applications ranging from consumer devices to industrial machinery.

2. Main Types and Functional Classification

Type	Functional Features	Application Examples
Unidirectional TVS	Protects against single-polarity transients	Power supplies, DC circuits
Bidirectional TVS	Clamps positive/negative transients simultaneously	AC lines, communication interfaces
Silicon-Controlled Rectifier (SCR)	Latching behavior for overvoltage crowbar protection	Power converters, motor drives
Triac	AC current control and bidirectional switching	Lighting control, HVAC systems

3. Structure and Composition

TVS diodes typically use a heavily doped PN junction structure with a large cross-sectional area to absorb transient energy. They are encapsulated in plastic packages (e.g., DO-214) with two terminals. Thyristors feature a four-layer PNPN structure with three terminals (anode, cathode, gate). Advanced models incorporate passivation layers and metal-over-glass packaging for thermal stability. Both devices use semiconductor materials like silicon, with doping profiles optimized for specific breakdown voltages.

4. Key Technical Specifications

Parameter	Description	Importance
Breakdown Voltage (Vbr)	Minimum voltage causing conduction	Matches protection level to circuit requirements
Clamping Voltage (Vc)	Voltage across device during conduction	Determines stress on protected components
Response Time	Time to transition from off to on state	Critical for protecting against fast transients
Surge Current Rating (Ipp)	Maximum allowable transient current	Ensures survival under worst-case scenarios
Holding Current (Ih)	Thyristor-specific: Maintains conduction state	Affects reset behavior in crowbar circuits

5. Application Fields

Key industries include:

Telecommunications: Ethernet transceivers, fiber optic modules
Industrial Automation: PLCs, motor drives
Consumer Electronics: Smartphones, power adapters
Automotive: CAN bus protection, alternator circuits
Renewable Energy: Solar inverters, wind turbine controllers

6. Leading Manufacturers and Products

Manufacturer	Representative Products	Key Features
Littelfuse	SM8S Series TVS	8kV ESD protection, low leakage current
STMicroelectronics	STRIP Series Thyristors	Integrated protection for AC loads
Vishay	TPSMB Series Bidirectional TVS	AEC-Q101 qualified for automotive use
ON Semiconductor	NUD3160 SCR	Integrated gate drive for crowbar circuits

7. Selection Guidelines

Key considerations:

Match breakdown voltage to system operating voltage (typically 10-15% higher)
Ensure clamping voltage is below the maximum rating of protected ICs
Select surge current capacity based on expected fault conditions
For thyristors: Evaluate holding current vs. load characteristics
Consider packaging (SMD vs. through-hole) for PCB integration

Example: For a 12V automotive circuit, a bidirectional TVS with 18V breakdown voltage and 40A surge rating would protect against load dump transients while surviving ISO 7637 test pulses.

8. Industry Trends

Emerging trends include:

Integration of TVS and EMI filtering in single packages
Wide bandgap materials (SiC/GaN) enabling higher temperature operation
Smart thyristors with integrated diagnostics for predictive maintenance
Miniaturization driven by 5G infrastructure and IoT device demands
Rail-to-rail protection architectures in high-speed data lines