TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
B72214S2231K101 TDK EPCOS	VARISTOR 360V 6KA DISC 14MM	1021
B72210S0551K101 TDK EPCOS	VARISTOR 910V 2.5KA DISC 10MM	927
B72205S0950K111 TDK EPCOS	VARISTOR 150V 400A DISC 5MM	0
B72205S0750K111 TDK EPCOS	VARISTOR 75VRMS 5MM RADIAL TR	0
B72240L0251K100 TDK EPCOS	VARISTOR 390V 40KA SQUARE 37.5MM	0
B72540T0110K062 TDK EPCOS	VARISTOR 18V 1.2KA 2220	244
B72207S0110K111 TDK EPCOS	VARISTOR 18V 250A DISC 7MM	1640
B72210P2511K101 TDK EPCOS	VARISTOR 820V 3.5KA DISC 10MM	0
B72530V0140K062 TDK EPCOS	VARISTOR 22V 400A 1210	0
B72660M0600S172 TDK EPCOS	VARISTOR 100V 1.2KA 4032	4418
B72214S0110K151 TDK EPCOS	VARISTOR 18V 1KA DISC 14MM	0
B72530T6250K062 TDK EPCOS	EIA1210, 36VDC, HIGH SURGE 1500A	5420
B72205S0131K111 TDK EPCOS	VARISTOR 205V 400A DISC 5MM	0
B72210U2381K502 TDK EPCOS	10MM, 385VAC, 10% ADVANCED, 125D	0
B72214S2321K551 TDK EPCOS	VARISTOR 510V 6KA DISC 14MM	1120
B72207S0170K211 TDK EPCOS	VARISTOR 27V 250A DISC 7MM	4904
B72210S0400K101 TDK EPCOS	VARISTOR 68V 500A DISC 10MM	11668
B72207S0271K101 TDK EPCOS	VARISTOR 430V 1.2KA DISC 7MM	5135
B72225M0151M201 TDK EPCOS	25MM, 150V, 20KA, THERMO FUSE TY	392
B72205S0231K111 TDK EPCOS	VARISTOR 360V 400A DISC 5MM	4839

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