TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
EZJ-Z0V420WA Panasonic	VARISTOR 42V 10A 0402	9000
ERZ-U21JP162H Panasonic	DELTATRANSIENT/SURGE ABSORBERS10	1
ERZ-E14A681S1 Panasonic	VARISTOR DISC 14MM 680V	985
ERZ-E10A821CS Panasonic	VARISTOR 820V 4.5KA DISC 12.50MM	0
ERZ-C20EK751Y Panasonic	VARISTOR 750V 8KA MODULE	20
ERZ-VF2M390 Panasonic	VARISTOR 39V 125A 2SMD JLEAD	0
ERZ-E08A241 Panasonic	VARISTOR 240V 3.5KA DISC 10.5MM	3108
ERZ-C40CK201W Panasonic	VARISTOR 200V 30KA DISC 40MM	0
ERZ-V14D271 Panasonic	VARISTOR 270V 6KA DISC 14MM	0
ERZ-E07A391CS Panasonic	VARISTOR 390V 2.5KA DISC 9MM	0
ERZ-E10A331 Panasonic	VARISTOR 330V 4.5KA DISC 11.5MM	1149
EZJ-PZV270BA Panasonic	VARISTOR 27V 1A 0201	14465
ERZ-E10F331 Panasonic	VARISTOR 330V 4.5KA DISC 11.5MM	0
ERZ-E11A271 Panasonic	VARISTOR 270V 6KA DISC 13MM	0
ERZ-V20D271 Panasonic	VARISTOR 270V 10KA DISC 20MM	0
ERZ-C32EK431Y Panasonic	VARISTOR 430V 25KA MODULE	11
ERZ-U21JP222H Panasonic	DELTATRANSIENT/SURGE ABSORBERS10	1
EZJ-Z0V80010 Panasonic	VARISTOR 80V 0402	13239
ERZ-E11A391 Panasonic	VARISTOR 390V 6KA DISC 13MM	0
ERZ-E08A221 Panasonic	VARISTOR 220V 3.5KA DISC 10.5MM	22

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