TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
B72214S0461K331 TDK EPCOS	VARISTOR 750V 4.5KA DISC 14MM	40
B72520E0200K062 TDK EPCOS	VARISTOR 33V 200A 1206	1638
B72207S0421K311 TDK EPCOS	VARISTOR 680V 1.2KA DISC 7MM	1945
B72510G1140S862 TDK EPCOS	AECQ200,VW80808-2, 120A,16V,0805	4860
B72210S2381K101 TDK EPCOS	VARISTOR 620V 3.5KA DISC 10MM	521
B72210S1140K102 TDK EPCOS	VARISTOR 22V 500A DISC 10MM	689
B72580V3140S272 TDK EPCOS	VARISTOR 22V 800A 1812	0
B72220T2271K101 TDK EPCOS	VARISTOR 430V 10KA RADIAL BOX	0
B72205S0600K101 TDK EPCOS	VARISTOR 100V 400A DISC 5MM	0
B72207S0950K211 TDK EPCOS	VARISTOR 150V 1.2KA DISC 7MM	0
B72280B0112K001 TDK EPCOS	VARISTOR 1.8KV 100KA ENCASE DISC	58
B72220S2231K101 TDK EPCOS	VARISTOR 360V 10KA DISC 20MM	1116
B72660M0250K072 TDK EPCOS	VARISTOR 39V 250A 2SMD JLEAD	4545
B72232B0551K001 TDK EPCOS	VARISTOR 910V 25KA ENCASED DISC	835
B72220S0271K551 TDK EPCOS	VARISTOR 430V 8KA DISC 20MM	704
B72205S0231K101 TDK EPCOS	VARISTOR 360V 400A DISC 5MM	5148
B72214S0750K151 TDK EPCOS	VARISTOR 120V 4.5KA DISC 14MM	1298
B72214P2141K102 TDK EPCOS	14MM, 140VAC, 10%, ADVANCED MP C	4882
B72530T0300K062 TDK EPCOS	VARISTOR 47V 300A 1210	192936
B72580T0131K072 TDK EPCOS	VARISTOR 205V 250A 1812	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