TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
B72220S3131K101 TDK EPCOS	VARISTOR 205V 12KA DISC 20MM	0
B72210S0321K151 TDK EPCOS	VARISTOR 510V 2.5KA DISC 10MM	3181
B72207S0600K311 TDK EPCOS	VARISTOR 100V 1.2KA DISC 7MM	0
B72214S2301K551 TDK EPCOS	VARISTOR 470V 6KA DISC 14MM	376
B72220S2950K101 TDK EPCOS	VARISTOR DISC 20MM	0
B72660M1300K072 TDK EPCOS	VARISTOR 47V 250A 2SMD JLEAD	6910
B72210S0321K551 TDK EPCOS	VARISTOR 510V 2.5KA DISC 10MM	911
B72210S0141K151 TDK EPCOS	VARISTOR 220V 2.5KA DISC 10MM	0
B72530G0350K062 TDK EPCOS	CT1210K35G_G	0
B72540T0060M062 TDK EPCOS	VARISTOR 11V 1.2KA 2220	0
B72582V0140K062 TDK EPCOS	VARISTOR 22V 800A 1812	0
B72250L0321K102 TDK EPCOS	VARISTOR 510V 75KA DISC 57MM	0
B72241L0461K100 TDK EPCOS	VARISTOR 750V 50KA DISC 40MM	0
B72530E1200K062 TDK EPCOS	VARISTOR 33V 400A 1210	0
B72240L0231K100 TDK EPCOS	VARISTOR 230VRMS 40MM W/TABS	0
B72530G1140S862 TDK EPCOS	AECQ200,VW80808-2, 400A,16V,1210	5885
B72220S2551K101 TDK EPCOS	VARISTOR 910V 10KA DISC 20MM	2250
B72214T2171K101 TDK EPCOS	VARISTOR 270V 6KA RADIAL BOX 3LD	0
B72440P5040S560 TDK EPCOS	VARISTOR 1A 0201	50145
B72210S0251K101 TDK EPCOS	VARISTOR 390V 2.5KA DISC 10MM	3467

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