TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
B72207S0421K101 TDK EPCOS	VARISTOR 680V 1.2KA DISC 7MM	3438
B72220S1390K501 TDK EPCOS	VARISTOR 65V DISC 20MM	0
B72210S0110K551 TDK EPCOS	VARISTOR 11VRMS 10MM RADIAL TR	4480
B72207S0301K311 TDK EPCOS	VARISTOR 470V 1.2KA DISC 7MM	65
B72214S0231K551 TDK EPCOS	VARISTOR 360V 4.5KA DISC 14MM	0
B72210S0600K101 TDK EPCOS	VARISTOR 100V 2.5KA DISC 10MM	1630
B72225T4211K101 TDK EPCOS	VARISTOR 330V 20KA RADIAL BOX	0
B72520T140K72 TDK EPCOS	VARISTOR 22V 200A 1206	0
B72570D0120A060 TDK EPCOS	VARISTOR 16V 20A 1003	7693
B72214S0350K151 TDK EPCOS	VARISTOR 56V 1KA DISC 14MM	6000
B72225S4621K101 TDK EPCOS	VARISTOR 1KV 20KA DISC 27.5MM	753
B72225S4151K101 TDK EPCOS	VARISTOR 240V 20KA DISC 27.5MM	905
B72214T2231K101 TDK EPCOS	VARISTOR 360V 6KA 3SIP	0
B72205S0950K101 TDK EPCOS	VARISTOR 150V 400A DISC 5MM	1779
B72207S0750K111 TDK EPCOS	VARISTOR 120V 1.2KA DISC 7MM	94186
B72230M0751M401 TDK EPCOS	30MM, 750V, 25KA, THERMO FUSE TY	400
B72660M0301K093 TDK EPCOS	VARISTOR 470V 1.2KA 2SMD JLEAD	2495
B72205S2950K101 TDK EPCOS	VARISTOR DISC 5MM	0
B72214S2551K101 TDK EPCOS	VARISTOR 910V 5KA DISC 14MM	3455
B72530E0200K062 TDK EPCOS	VARISTOR 33V 400A 1210	920

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