TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
B72660M0300K093 TDK EPCOS	VARISTOR 47V 250A 4032	0
B72650M0131K093 TDK EPCOS	VARISTOR 205V 400A 3225	0
B72520E1140S262 TDK EPCOS	VARISTOR 24.5V 200A 1206	3194
B72214S0301K551 TDK EPCOS	VARISTOR 470V 4.5KA DISC 14MM	3000
B72220S0151K101 TDK EPCOS	VARISTOR 240V 8KA DISC 20MM	995
B72500E8250L060 TDK EPCOS	VARISTOR 61V 5A 0603	4943
B72220Q0171K101 TDK EPCOS	VARISTOR 270V 15KA RADIAL	1637
B72582V0350K062 TDK EPCOS	VARISTOR 56V 500A 1812	0
B72220T2141K101 TDK EPCOS	VARISTOR 220V 10KA RADIAL BOX	0
B72205S0301K211 TDK EPCOS	VARISTOR 470V 400A DISC 5MM	40153
B72214S0750K551 TDK EPCOS	VARISTOR 120V 4.5KA DISC 14MM	4500
B72205S0421K101 TDK EPCOS	VARISTOR 680V 400A DISC 5MM	0
B72214S0381K551 TDK EPCOS	VARISTOR 620V 4.5KA DISC 14MM	2540
B72580E0140K062 TDK EPCOS	VARISTOR 22V 800A 1812	3341
B72510G0250K062 TDK EPCOS	CT0805K25G_G	0
B72214S0500K151 TDK EPCOS	VARISTOR 82V 4.5KA DISC 14MM	62657
B72205S0271K311 TDK EPCOS	VARISTOR 430V 400A DISC 5MM	6332
B72214U2381K502 TDK EPCOS	14MM, 385VAC, 10% ADVANCED, 125D	910
B72260B0321K001 TDK EPCOS	VARISTOR 510V 70KA ENCASED DISC	22
B72210S0600K501 TDK EPCOS	VARISTOR 100V 2.5KA DISC 10MM	1498

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