TVS - Varistors, MOVs

Image	Part Number	Description / PDF	Quantity	Rfq
	VDRH20X150BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 240V 10KA DISC 22.50MM	0
	VDRS14T300ASE Vishay BC Components/Beyshlag/Draloric	VARISTOR 470V 4.5KA DISC 16MM	0
	VDRS10P175TSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 275V 2.5KA DISC 12MM	0
	VDRS07B040BKE Vishay BC Components/Beyshlag/Draloric	VARISTOR 68V 250A DISC 9MM	0
	VDRS07H230TSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 360V 1.2KA DISC 9MM	0
	VDRS14T320TLE Vishay BC Components/Beyshlag/Draloric	VARISTOR 510V 4.5KA DISC 16MM	0
	VDRS05C275TLE Vishay BC Components/Beyshlag/Draloric	VARISTOR 430V 400A DISC 7MM	0
	VDRS07B035AGE Vishay BC Components/Beyshlag/Draloric	VARISTOR 56V 250A DISC 9MM	0
	VDRS07H060TME Vishay BC Components/Beyshlag/Draloric	VARISTOR 100V 1.2KA DISC 9MM	0
	VDRS14T350BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 560V 4.5KA DISC 16.5MM	0
	VDRH10S275TME Vishay BC Components/Beyshlag/Draloric	VARISTOR 430V 3.5KA DISC 12MM	0
	VDRS20M035BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 56V 2KA DISC 22.50MM	0
	VDRS20W320BKE Vishay BC Components/Beyshlag/Draloric	VARISTOR 510V 6.5KA DISC 22.50MM	0
	VDRS07H250BKE Vishay BC Components/Beyshlag/Draloric	VARISTOR 390V 1.2KA DISC 9MM	0
	VDRS10P510TSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 820V 2.5KA DISC 12.50MM	0
	VDRH20X115BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 180V 10KA DISC 22.50MM	0
	VDRS10D014BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 22V 500A DISC 12MM	0
	MLV0603E31103T Vishay BC Components/Beyshlag/Draloric	VARISTOR 18V 30A 0603	0
	VDRH10S300TME Vishay BC Components/Beyshlag/Draloric	VARISTOR 470V 3.5KA DISC 12MM	0
	VDRS10P150TLE Vishay BC Components/Beyshlag/Draloric	VARISTOR 240V 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