TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-E10E271 Panasonic	VARISTOR 270V 4.5KA DISC 11.5MM	0
ERZ-V07D330 Panasonic	VARISTOR 33V 500A DISC 7MM	0
ERZ-V09D680 Panasonic	VARISTOR 68V 1KA DISC 10MM	0
ERZ-C20EK271Y Panasonic	VARISTOR 270V 8KA MODULE	10
ERZ-V10D361 Panasonic	VARISTOR 360V 3.5KA DISC 10MM	83
ERZ-V20D680 Panasonic	VARISTOR 68V 3KA DISC 20MM	8110
ERZ-E11A391CS Panasonic	VARISTOR 390V 6KA DISC 13MM	0
ERZ-V05D560 Panasonic	VARISTOR 56V 250A DISC 5MM	298
ERZ-E08A241CS Panasonic	VARISTOR 240V 3.5KA DISC 10.5MM	0
ERZ-E07A471 Panasonic	VARISTOR 470V 2.5KA DISC 9MM	0
ERZ-V10D102 Panasonic	VARISTOR 1KV 3.5KA DISC 10MM	0
ERZ-U25JP132F Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-E14A471 Panasonic	VARISTOR 470V 10KA DISC 16.5MM	0
ERZ-VF2M241 Panasonic	VARISTOR 240V 600A 2SMD JLEAD	1484
ERZ-V05D330 Panasonic	VARISTOR 33V 250A DISC 5MM	9
ERZ-CF2MK560 Panasonic	VARISTOR 56V 50A 2SMD JLEAD	730
ERZ-V07D820 Panasonic	VARISTOR 82V 1.75KA DISC 7MM	0
ERZ-V10D471 Panasonic	VARISTOR 470V 3.5KA DISC 10MM	51728
ERZ-E10A681 Panasonic	VARISTOR 680V 4.5KA DISC 12.50MM	3858
ERZ-V14D241 Panasonic	VARISTOR 240V 6KA DISC 14MM	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