TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
VDRS14T460BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 750V 4.5KA DISC 16.5MM	520
MLV0402E30403T Vishay BC Components/Beyshlag/Draloric	VARISTOR 8.2V 20A 0402	23444
VDRUS07M320BKE Vishay BC Components/Beyshlag/Draloric	VDR US 07D 1800A 320V KNLDS	0
VDRUS10T420BKE Vishay BC Components/Beyshlag/Draloric	VDR US 10D 4500A 420V KNLDS	0
VDRS14G020TSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 33V 1KA DISC 16MM	0
VDRUS14X150BSE Vishay BC Components/Beyshlag/Draloric	VDR US 14D 8000A 150V STLDS BULK	965
VDRUS14X320BKE Vishay BC Components/Beyshlag/Draloric	VDR US 14D 8000A 320V KNLDS	0
VDRUS14X510BKE Vishay BC Components/Beyshlag/Draloric	VDR US 14D 8000A 510V KNLDS	0
VDRS05C275TSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 430V 400A DISC 7MM	4500
VDRH20X300BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 470V 10KA DISC 22.50MM	466
VDRUS07M140BKE Vishay BC Components/Beyshlag/Draloric	VDR US 07D 1800A 140V KNLDS	0
VDRS05A035BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 56V 100A DISC 7MM	0
VDRS05C140BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 220V 400A DISC 7MM	0
VDRS10D035BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 56V 500A DISC 12MM	0
VDRUS14X275BKE Vishay BC Components/Beyshlag/Draloric	VDR US 14D 8000A 275V KNLDS	0
VDRS05C300BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 470V 400A DISC 7MM	0
VDRH10S300BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 470V 3.5KA DISC 12MM	2140
VDRS10P230BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 360V 2.5KA DISC 12MM	0
VDRUS07M230BKE Vishay BC Components/Beyshlag/Draloric	VDR US 07D 1800A 230V KNLDS	0
VDRUS07M300BSE Vishay BC Components/Beyshlag/Draloric	VDR US 07D 1800A 300V STLDS BULK	1802

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