TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
B72280B0461K001 TDK EPCOS	VARISTOR 750V 100KA ENCASED DISC	4
B72580T0600S172 TDK EPCOS	VARISTOR 100V 400A 1812	0
B72214P2381K102 TDK EPCOS	14MM, 385VAC, 10%, ADVANCED MP C	3908
B72542V3140S272 TDK EPCOS	VARISTOR 22V 1.2KA 2220	0
B72214P2301K101 TDK EPCOS	VARISTOR 470V 6KA DISC 14MM	28713
B72660M0500K072 TDK EPCOS	VARISTOR 82V 1.2KA 2SMD JLEAD	1234
B72214P2271K101 TDK EPCOS	VARISTOR 430V 6KA DISC 14MM	0
B72220S0950K101 TDK EPCOS	VARISTOR 150V 6.5KA DISC 20MM	0
B72214S0381K501 TDK EPCOS	VARISTOR 620V 4.5KA DISC 14MM	0
B72210S1140K151 TDK EPCOS	VARISTOR 22V 500A DISC 10MM	0
B72230M0321M401 TDK EPCOS	30MM, 320V, 25KA, THERMO FUSE TY	330
B72220T2211K101 TDK EPCOS	VARISTOR 330V 10KA RADIAL BOX	0
B72214P2231K101 TDK EPCOS	VARISTOR 360V 6KA DISC 14MM	2860
B72520T0080L062 TDK EPCOS	VARISTOR 15V 200A 1206	4456
B72220S0131K101 TDK EPCOS	VARISTOR 205V 8KA DISC 20MM	9015
B72205S0151K101 TDK EPCOS	VARISTOR 240V 400A DISC 5MM	3625
B72250L0421K100 TDK EPCOS	VARISTOR 680V 75KA DISC 57MM	0
B72210S0511K101 TDK EPCOS	VARISTOR 820V 2.5KA DISC 10MM	2394
B72205S0300K101 TDK EPCOS	VARISTOR 47V 100A DISC 5MM	714
B72660M0171K072 TDK EPCOS	VARISTOR 270V 1.2KA 2SMD JLEAD	12864

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