TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
AVRM0603C120MT101N TDK Corporation	VARISTOR 12V 5A 0201	15827
AVR-M1005C270MTAAB TDK Corporation	VARISTOR 27V 4A 0402	18418
VAR-18094077M3P-XK TDK Corporation	VARISTOR 7.65V RING SURFACE ELEC	0
AVR-M2012C220KT6AB TDK Corporation	VARISTOR 22V 100A 0805	3472
VAR-18080077M3P-XK TDK Corporation	VARISTOR 7.65V RING SURFACE ELEC	0
VAR-18107157M3P-XK TDK Corporation	VARISTOR 15.7V RING SURFACE ELEC	0
VAR-18080115M3P-XK TDK Corporation	VARISTOR 11.5V RING SURFACE ELEC	0
AVR-M1005C180MTAAB TDK Corporation	VARISTOR 18V 16A 0402	5187
VAR-18042077M3P-XK TDK Corporation	VARISTOR 7.65V RING SURFACE ELEC	0
AVR-M1608C220KT6AB TDK Corporation	VARISTOR 22V 48A 0603	16768
AVR-M1608C080MTAAB TDK Corporation	VARISTOR 8V 30A 0603	170111
VAR-18120320M5P-XK TDK Corporation	VARISTOR 32V RING SURFACE ELECT	41
VAR-18107320M3P-XK TDK Corporation	VARISTOR 32V RING SURFACE ELECT	0
AVRL101D6R8GTA TDK Corporation	COMMERCIAL GRADE MULTILAYER CHIP	18760
AVRM1005C270KT101N TDK Corporation	VARISTOR 27V 4A 0402	14834
VAR-18107077M3P-XK TDK Corporation	VARISTOR 7.65V RING SURFACE ELEC	0
AVRM0402C6R8NT101N TDK Corporation	COMMERCIAL GRADE, MULTILAYER CHI	19964
VAR-18107115M3P-XK TDK Corporation	VARISTOR 11.5V RING SURFACE ELEC	80
AVR-M1005C120MTACC TDK Corporation	VARISTOR 12V 24A 0402	6009
AVR-M1005C080MTAAB TDK Corporation	VARISTOR 8V 25A 0402	42634

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