TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
VAR-18160550M5P-XK TDK Corporation	VARISTOR 50V RING SURFACE ELECT	0
AVRL101D3R3FTA TDK Corporation	COMMERCIAL GRADE MULTILAYER CHIP	21139
AVRM2012C720KT201M TDK Corporation	AUTO. GRADE,MLV,200PF,53VDC,0805	7455
AVR-M1005C270MTABB TDK Corporation	VARISTOR 27V 1A 0402	17178
AVRM1005C6R8NT331N TDK Corporation	VARISTOR 6.8V 24A 0402	13236
AVRL161A6R8GTA TDK Corporation	VARISTOR 27V 0603	9265
AVRM0603C6R8NT101N TDK Corporation	VARISTOR 6.8V 10A 0201	5719
AVRL161D3R3FTA TDK Corporation	COMMERCIAL GRADE MULTILAYER CHIP	5890
AVR-M1005C080MTADB TDK Corporation	VARISTOR 8V 25A 0402	3993
AVRM2012C560KT251M TDK Corporation	AUTO. GRADE,MLV,250PF,40VDC,0805	6030
SGNE06C270MT6R8G60 TDK Corporation	VARISTOR 27V 0201	11775
AVR-M1608C120MT2AB TDK Corporation	VARISTOR 12V 15A 0603	64305
AVRM1608C270KT800M TDK Corporation	VARISTOR 27V 28A 0603	3990
AVR-M1608G270KT6AB TDK Corporation	AUTO. GRADE,MLV,430PF,19VDC,0805	8000
AVR-M1005C080MTABB TDK Corporation	VARISTOR 8V 3A 0402	143407
AVR-M2012C120MT6AB TDK Corporation	VARISTOR 12V 60A 0805	5282
AVR-M1005C080MTACB TDK Corporation	VARISTOR 8V 1A 0402	11794
VAR-18085218M3P-XK TDK Corporation	VARISTOR 21.8V RING SURFACE ELEC	45
AVRM1608C270KT221M TDK Corporation	VARISTOR 27V 56A 0603	6301
AVR-M1608C270KTACB TDK Corporation	VARISTOR 27V 10A 0603	3965

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