TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
V07E300PL1B5 Wickmann / Littelfuse	VARISTOR 470V 1.75KA DISC 7MM	0
B72207S0200K101 TDK EPCOS	VARISTOR 33V 250A DISC 7MM	4417
V18AUMLA1210NA Wickmann / Littelfuse	VARISTOR 27.5V 1210	0
V05E14P Wickmann / Littelfuse	VARISTOR 22V 500A DISC 5MM	0
MVR14D680K-S Meritek	VARISTOR 68V 2000A DISC 14MM HIG	0
V30MLA0805LNT Wickmann / Littelfuse	VARISTOR 41.5V 30A 0805	0
ERZ-E05A271 Panasonic	VARISTOR 270V 1.2KA DISC 7MM	9922
VC2220K122R020 KEMET	VARISTOR 33V 1.2KA 2220	0
B72207S0500K311 TDK EPCOS	VARISTOR 82V 1.2KA DISC 7MM	0
102KD10 Yageo	MOV	0
ERZ-V14D390 Panasonic	VARISTOR 39V 2KA DISC 14MM	12395
B72214S2551K551 TDK EPCOS	VARISTOR 910V 5KA DISC 14MM	1407
B72205U2151K501 TDK EPCOS	VARISTOR 240V 800A DISC 5MM	838
CG0402MLC-24LG J.W. Miller / Bourns	VARISTOR 0402	29735
ERZ-E10B201CS Panasonic	VARISTOR 200V 4.5KA DISC 11.5MM	0
B72214S0301K531 TDK EPCOS	VARISTOR 470V 4.5KA DISC 14MM	3887
V10H115P Wickmann / Littelfuse	VARISTOR 180V 3.5KA DISC 10MM	0
B72205S0151K211 TDK EPCOS	VARISTOR 240V 400A DISC 5MM	145
B72207S0950K111 TDK EPCOS	VARISTOR 150V 1.2KA DISC 7MM	2982
B72530G1140S262 TDK EPCOS	VARISTOR MLV 1210	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