TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
AVRM0603C120MT150N TDK Corporation	VARISTOR 12V 1A 0201	9145
AVRM1608C560KT101M TDK Corporation	AUTO. GRADE,MLV,100PF,40VDC,0805	7888
AVRL101A1R1NTB TDK Corporation	VARISTOR 39V 0402	24
AVRM1608C390KT271N TDK Corporation	VARISTOR 39V 78A 0603	12250
AVR-M0603C120MTAAB TDK Corporation	VARISTOR 12V 1A 0201	9309
VAR-18120550M5P-XK TDK Corporation	VARISTOR 50V RING SURFACE ELECT	27
AVR-M1608C220KT2AB TDK Corporation	VARISTOR 22V 10A 0603	2065
VAR-18160320M5P-XK TDK Corporation	VARISTOR 32V RING SURFACE ELECT	0
VAR-18086157M3S-XK TDK Corporation	VARISTOR 15.7V RING SIDE ELECT	89
SGNE06C080MT150N25 TDK Corporation	VARISTOR 8V 0201	14900
VAR-18042077M3S-XK TDK Corporation	VARISTOR 7.65V RING SIDE ELECT	90
AVRH10C390KT500NA8 TDK Corporation	VARISTOR 39V 15A 0402	2263
AVF16C212A000F205 TDK Corporation	VARISTOR 12V 0603	0
AVR-M14A2C240MT600N TDK Corporation	VARISTOR 24V 5A 1410	0
AVF16C225A000F405 TDK Corporation	VARISTOR 25V 0603	0
VAR-18085077M3P-YK TDK Corporation	VARISTOR 7.65V RING SURFACE ELEC	0

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