TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
B72214S0600K551 TDK EPCOS	VARISTOR 100V 4.5KA DISC 14MM	3950
B72660M0271K072 TDK EPCOS	VARISTOR 430V 1.2KA 2SMD JLEAD	588
B72214P2211K101 TDK EPCOS	VARISTOR 330V 6KA DISC 14MM	0
B72240L0151K100 TDK EPCOS	VARISTOR 240V 40KA SQUARE 37.5MM	777
B72530U1500K062 TDK EPCOS	EIA1210, 65VDC, HIGH SURGE 1200A	10571
B72650M0110K072 TDK EPCOS	VARISTOR 18V 100A 2SMD JLEAD	3747
B72210S0140K151 TDK EPCOS	VARISTOR 22V 500A DISC 10MM	2763
B72214S0600K501 TDK EPCOS	VARISTOR 100V 4.5KA DISC 14MM	0
B72210S0600K551 TDK EPCOS	VARISTOR 100V 2.5KA DISC 10MM	0
B72214W2321K101 TDK EPCOS	VARISTOR 510V 6KA DISC 17MM	354
B72205S0271K111 TDK EPCOS	VARISTOR 430V 400A DISC 5MM	2320
B72214S0500K101 TDK EPCOS	VARISTOR 82V 4.5KA DISC 14MM	6239
B72520T250K72 TDK EPCOS	VARISTOR 39V 200A 1206	0
B72214P2141K101 TDK EPCOS	VARISTOR 220V 6KA DISC 14MM	5592
B72205S2141K101 TDK EPCOS	VARISTOR 220V 800A DISC 5MM	0
B72207S0750K211 TDK EPCOS	VARISTOR 120V 1.2KA DISC 7MM	4309
B72210S0140K551 TDK EPCOS	VARISTOR 22V 500A DISC 10MM	0
B72240L0421K100 TDK EPCOS	VARISTOR 420VRMS 40MM W/TABS	0
B72205S0400K211 TDK EPCOS	VARISTOR 68V 100A DISC 5MM	0
B72210S0681K351 TDK EPCOS	VARISTOR 1.1KV 2.5KA DISC 10MM	3016

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