TVS - Varistors, MOVs

Image	Part Number	Description / PDF	Quantity	Rfq
	VDRH20X385BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 620V 10KA DISC 23MM	0
	VDRS07B017TSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 27V 250A DISC 9MM	0
	VDRS07B030TSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 47V 250A DISC 9MM	0
	VDRS07B014BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 22V 250A DISC 9MM	0
	VDRS05C130TSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 205V 400A DISC 7MM	0
	VDRS07H060TSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 100V 1.2KA DISC 9MM	0
	VDRH14V350BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 560V 6KA DISC 16.5MM	0
	VDRH14V420BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 680V 6KA DISC 16.5MM	0
	VDRS07H300ASE Vishay BC Components/Beyshlag/Draloric	VARISTOR 470V 1.2KA DISC 9MM	0
	VDRH14V275BKE Vishay BC Components/Beyshlag/Draloric	VARISTOR 430V 6KA DISC 16MM	0
	VDRS14T250ALE Vishay BC Components/Beyshlag/Draloric	VARISTOR 390V 4.5KA DISC 16MM	0
	VDRS07H275TLE Vishay BC Components/Beyshlag/Draloric	VARISTOR 430V 1.2KA DISC 9MM	0
	VDRS10P460ASE Vishay BC Components/Beyshlag/Draloric	VARISTOR 750V 2.5KA DISC 12.50MM	0
	VDRS14G035TME Vishay BC Components/Beyshlag/Draloric	VARISTOR 56V 1KA DISC 16MM	0
	VDRS07H075TME Vishay BC Components/Beyshlag/Draloric	VARISTOR 120V 1.2KA DISC 9MM	0
	VDRH14V420BKE Vishay BC Components/Beyshlag/Draloric	VARISTOR 680V 6KA DISC 16.5MM	0
	VDRS10P150TME Vishay BC Components/Beyshlag/Draloric	VARISTOR 240V 2.5KA DISC 12MM	0
	VDRH10S300TSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 470V 3.5KA DISC 12MM	0
	VDRS07H230TGE Vishay BC Components/Beyshlag/Draloric	VARISTOR 360V 1.2KA DISC 9MM	0
	VDRS10P300TLE Vishay BC Components/Beyshlag/Draloric	VARISTOR 470V 2.5KA DISC 12MM	0

TVS - Varistors, MOVs

1. Overview

Transient Voltage Suppressors (TVS), Varistors, and Metal Oxide Varistors (MOVs) are critical components for protecting electronic circuits from voltage spikes and electrostatic discharge (ESD). These devices clamp excessive voltage to safe levels, preventing damage to sensitive components. TVS diodes are semiconductor-based solutions with fast response times, while Varistors (including MOVs) use nonlinear resistive materials to absorb energy. Their importance spans industries like telecommunications, automotive, and consumer electronics, ensuring reliability in environments exposed to electrical surges.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
TVS Diodes	Unidirectional/bidirectional clamping, sub-nanosecond response time, low leakage current	Communication interfaces (USB, HDMI), microcontrollers, power supplies
Zinc Oxide Varistors	High energy absorption, voltage-dependent resistance, aging characteristics	Power line protection, industrial motor drives, surge protection strips
MOVs	Specialized varistors with metal oxide ceramics, optimized for AC/DC applications	Appliances, LED lighting, renewable energy systems

3. Structure and Composition

TVS diodes employ a PN junction semiconductor structure with doping profiles optimized for breakdown characteristics. Varistors consist of polycrystalline ceramic materials (typically zinc oxide grains with additives) sandwiched between metal electrodes, encapsulated in epoxy or molded housings. MOVs use similar materials to varistors but with enhanced grain boundary engineering for improved voltage clamping. All devices incorporate termination coatings (e.g., silver, tin) for PCB mounting compatibility.

4. Key Technical Parameters

Parameter	Description	Importance
Clamping Voltage (V_CLAMP)	Voltage level during surge conduction	Determines protection level for downstream components
Response Time	Time to transition from blocking to clamping mode	TVS: 0.5-10 ns; MOVs: 10-50 ns
Energy Absorption (W_ADM)	Maximum surge energy handling capability	Measured in joules (J), critical for industrial applications
Leakage Current	Off-state current at rated voltage	Impacts power efficiency, typically <100 A

5. Application Fields

Key industries include:

Consumer Electronics: Smartphone charging circuits, TV power supplies
Industrial Automation: PLCs, motor drives, sensor interfaces
Automotive: ECU protection, CAN bus interfaces, battery management systems
Renewable Energy: Solar inverters, wind turbine controllers

Case Study: MOVs in smart meters provide 10kA surge protection against grid transients.

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Specifications
Littelfuse	SM712-02	12A, 13.3V clamping, bidirectional TVS for RS-485
Bourns	V14450A	14mm MOV, 450VAC, 210J energy rating
STMicroelectronics	TV05C060	0.5W, 6V, ultra-small TVS for IoT devices

7. Selection Guidelines

Key considerations:

Operating voltage vs. clamping voltage margin
Surge current requirements (8/20 s waveform standard)
Package size constraints (SMD vs. through-hole)
Environmental conditions (temperature, humidity)
Lifespan expectations (MOVs degrade with repeated surges)

8. Industry Trends

Emerging trends include:

Miniaturization: Sub-0201 TVS devices for mobile applications
Higher energy density: MOVs with >1000J/cm absorption
Integration: Combined ESD and surge protection solutions
Automotive focus: AEC-Q qualified devices for 48V systems
Green manufacturing: Lead-free and RoHS-compliant materials