TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
MVR20D821K Meritek	VARISTOR 820V 6500A 20MM DISC TH	0
MVR14D220K Meritek	VARISTOR 22V 1KA 14MM DISC THRU	2250
MVR14D112K-S Meritek	VARISTOR 1100V 6000A DISC 14MM H	0
MVR07D391K-S Meritek	VARISTOR 390V 1750A DISC 7MM HIG	0
MVR20D361K-S Meritek	VARISTOR 360V 10000A DISC 20MM H	0
MVR20D151K-S Meritek	VARISTOR 150V 10000A DISC 20MM H	0
MVR10D471K-S Meritek	VARISTOR 470V 3500A DISC 10MM HI	0
MVR20D121K-S Meritek	VARISTOR 120V 10000A DISC 20MM H	0
MVR20D102K Meritek	VARISTOR 1000V 6500A 20MM DISC T	0
MVR07D270K-S Meritek	VARISTOR 27V 500A DISC 7MM HIGH	0
MVR14D271K-S Meritek	VARISTOR 270V 6000A DISC 14MM HI	0
MVR20D361K Meritek	VARISTOR 360V 6500A 20MM DISC TH	0
MVR05D241K-S Meritek	VARISTOR 240V 800A DISC 5MM HIGH	0
MVR14D151K Meritek	VARISTOR 150V 4500A 14MM DISC TH	1500
MVR07D681K-S Meritek	VARISTOR 680V 1750A DISC 7MM HIG	0
MVR07D390K Meritek	VARISTOR 39V 250A 7MM DISC THRU	0
MVR07D751K Meritek	VARISTOR 750V 1200A 7MM DISC THR	0
MVR14D162K-S Meritek	VARISTOR 1600V 6000A DISC 14MM H	0
MVR14D751K Meritek	VARISTOR 750V 4500A 14MM DISC TH	0
MVR10D301K-S Meritek	VARISTOR 300V 3500A DISC 10MM HI	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