TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
MVR20D471K Meritek	VARISTOR 470V 6500A 20MM DISC TH	0
MVR20D181K Meritek	VARISTOR 180V 6500A 20MM DISC TH	0
MVR14D331K Meritek	VARISTOR 330V 4500A 14MM DISC TH	0
MVR07D220K-S Meritek	VARISTOR 22V 500A DISC 7MM HIGH	0
MVR20D180K-S Meritek	VARISTOR 18V 3000A DISC 20MM HIG	0
MVR20D511K Meritek	VARISTOR 510V 6500A 20MM DISC TH	2000
MVR14D121K-S Meritek	VARISTOR 120V 6000A DISC 14MM HI	0
MVR10D431K Meritek	VARISTOR 430V 2500A 10MM DISC TH	0
MVR05D151K-S Meritek	VARISTOR 150V 800A DISC 5MM HIGH	0
MVR05D331K Meritek	VARISTOR 330V 400A 5MM DISC THRU	0
MVR20D241K-S Meritek	VARISTOR 240V 10000A DISC 20MM H	1000
MVR07D561K Meritek	VARISTOR 560V 1200A 7MM DISC THR	0
MVR14D221K-S Meritek	VARISTOR 220V 6000A DISC 14MM HI	0
MVR14D751K-S Meritek	VARISTOR 750V 6000A DISC 14MM HI	0
MVR10D911K-S Meritek	VARISTOR 910V 3500A DISC 10MM HI	0
MVR14D270K-S Meritek	VARISTOR 27V 2000A DISC 14MM HIG	0
MVR07D151K-S Meritek	VARISTOR 150V 1750A DISC 7MM HIG	0
MVR14D162K Meritek	VARISTOR 1600V 4500A 14MM DISC T	0
MVR20D820K Meritek	VARISTOR 82V 6500A 20MM DISC THR	2500
MVR10D390K Meritek	VARISTOR 39V 500A 10MM DISC THRU	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