TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
B72500E5200S160 TDK EPCOS	VARISTOR 36V 30A 0603	4429
B72214S2151K151 TDK EPCOS	VARISTOR 240V 6KA DISC 14MM	2999
B72205S0441K101 TDK EPCOS	VARISTOR 715V 400A DISC 5MM	0
B72210S2421K101 TDK EPCOS	VARISTOR 680V 3.5KA DISC 10MM	1720
B72207S0151K111 TDK EPCOS	VARISTOR 240V 1.2KA DISC 7MM	5671
B72440P5040S460 TDK EPCOS	VARISTOR 27V 1A 0201	6222
B72207S0170K101 TDK EPCOS	VARISTOR 27V 250A DISC 7MM	721
B72210S0171K501 TDK EPCOS	VARISTOR 270V 2.5KA DISC 10MM	0
B72214S2301K101 TDK EPCOS	VARISTOR 470V 6KA DISC 14MM	12849
B72510T0300K062 TDK EPCOS	VARISTOR 47V 80A 0805	73304
B72660M0600K093 TDK EPCOS	VARISTOR 100V 1.2KA 4032	0
B72205S0301K321 TDK EPCOS	VARISTOR 470V 400A DISC 5MM	0
B72590D0150H060 TDK EPCOS	VARISTOR 23V 0402	4640
B72230M0681M401 TDK EPCOS	30MM, 680V, 25KA, THERMO FUSE TY	280
B72220T2271K105 TDK EPCOS	VARISTOR 430V 10KA RADIAL BOX	37
B72500P8200S060 TDK EPCOS	EIA0603, AUTOETHERNET 100BASE-T1	7996
B72214S1140K501 TDK EPCOS	VARISTOR 22V 1KA DISC 14MM	2988
B72240L0131K100 TDK EPCOS	VARISTOR 205V 40KA SQUARE 37.5MM	95
B72210S0750K151 TDK EPCOS	VARISTOR 120V 2.5KA DISC 10MM	2397
B72214T2231K105 TDK EPCOS	VARISTOR 360V 6KA 3SIP	340

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