TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
B72210S0500K531 TDK EPCOS	VARISTOR 82V 2.5KA DISC 10MM	0
B72580T0500K062 TDK EPCOS	VARISTOR 82V 400A 1812	4326
B72214U2271K501 TDK EPCOS	VARISTOR 430V 6KA DISC 14MM	2313
B72225S4381K101 TDK EPCOS	VARISTOR 620V 20KA DISC 27.5MM	0
B72220S0231K551 TDK EPCOS	VARISTOR 360V 8KA DISC 20MM	0
B72220S0421K101 TDK EPCOS	VARISTOR 680V 8KA DISC 20MM	0
B72530E1250K062 TDK EPCOS	VARISTOR 39V 300A 1210	0
B72650M0171K072 TDK EPCOS	VARISTOR 270V 400A 3225	1798
B72210S0131K151 TDK EPCOS	VARISTOR 205V 2.5KA DISC 10MM	2600
B72214S0511K331 TDK EPCOS	VARISTOR 820V 4.5KA DISC 14MM	500
B72232B0321K001 TDK EPCOS	VARISTOR 510V 25KA ENCASED DISC	1519
B72280B0251K001 TDK EPCOS	VARISTOR 390V 100KA ENCASED DISC	8
B72210S0251K211 TDK EPCOS	VARISTOR 390V 2.5KA DISC 10MM	3450
B72220T2351K101 TDK EPCOS	VARISTOR 560V 10KA RADIAL BOX	0
B72660M1140K072 TDK EPCOS	VARISTOR 22V 250A 2SMD JLEAD	3000
B72510E0300K062 TDK EPCOS	VARISTOR 47V 80A 0805	6663
B72530T0080L062 TDK EPCOS	VARISTOR 15V 400A 1210	0
B72205S0350K101 TDK EPCOS	VARISTOR 56V 100A DISC 5MM	1643
B72220S0200K131 TDK EPCOS	VARISTOR 33V 2KA DISC 20MM	4374
B72650M0170K072 TDK EPCOS	VARISTOR 27V 100A 3225	1654

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