TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
B72214Q0211K101 TDK EPCOS	VARISTOR 330V 8KA RADIAL	0
B72205S0140K101 TDK EPCOS	VARISTOR 22V 100A DISC 5MM	290
B72250L0131K102 TDK EPCOS	VARISTOR 205V 75KA DISC 57MM	26
B72214T2271K105 TDK EPCOS	VARISTOR 430V 6KA 3SIP	1598
B72214S0170K151 TDK EPCOS	VARISTOR 27V 1KA DISC 14MM	2879
B72220P3681K101 TDK EPCOS	VARISTOR 1.1KV 10KA DISC 20MM	0
B72530G0170K062 TDK EPCOS	VARISTOR MLV 1210	0
B72205S0200K211 TDK EPCOS	VARISTOR 33V 100A DISC 5MM	0
B72542V6600K062 TDK EPCOS	CN2220K60E2GK2	0
B72530E1170K062 TDK EPCOS	VARISTOR 27V 400A 1210	0
B72230M0421M401 TDK EPCOS	30MM, 420V, 25KA, THERMO FUSE TY	320
B72520T0300K062 TDK EPCOS	VARISTOR 47V 200A 1206	45056
B72280B0421K001 TDK EPCOS	VARISTOR 680V 100KA ENCASED DISC	1
B72210S2511K101 TDK EPCOS	VARISTOR 820V 3.5KA DISC 10MM	0
B72232B0441K001 TDK EPCOS	VARISTOR 715V 25KA ENCASED DISC	0
B72214S0400K151 TDK EPCOS	VARISTOR 68V 1KA DISC 14MM	3597
B72210S0141K551 TDK EPCOS	VARISTOR 220V 2.5KA DISC 10MM	0
B72500D0050A060 TDK EPCOS	VARISTOR 6.4V 30A 0603	30286
B72214S0251K151 TDK EPCOS	VARISTOR 390V 4.5KA DISC 14MM	17
B72210S0111K101 TDK EPCOS	VARISTOR 180V 2.5KA DISC 10MM	1141

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