TVS - Varistors, MOVs

Image	Part Number	Description / PDF	Quantity	Rfq
	ERZ-CF2MK431 Panasonic	VARISTOR 430V 200A 2SMD JLEAD	0
	ERZ-SF2MK470 Panasonic	VARISTOR 47V 125A 2SMD JLEAD	0
	EZJ-Z0V270AA Panasonic	VARISTOR 27V 0402	0
	ERZ-SF2MK270 Panasonic	VARISTOR 27V 125A 2SMD JLEAD	0
	ERZ-C20DK621U Panasonic	VARISTOR 620V 6.5KA DISC 20MM	0
	ERZ-C07DK221U Panasonic	VARISTOR 220V 1.2KA DISC 7MM	0
	ERZ-SF2MK820 Panasonic	VARISTOR 82V 600A 2SMD JLEAD	0
	ERZ-SF2MK560 Panasonic	VARISTOR 56V 125A 2SMD JLEAD	0
	ERZ-CF2MK151 Panasonic	VARISTOR 150V 200A 2SMD JLEAD	0
	ERZ-VF2T241 Panasonic	VARISTOR 240V 400A 2SMD JLEAD	0
	ERZ-SF2MK330 Panasonic	VARISTOR 33V 125A 2SMD JLEAD	0
	EZJ-ZZV120EA Panasonic	VARISTOR 12V 1A 0201	0
	ERZ-SF2MK221 Panasonic	VARISTOR 220V 600A 2SMD JLEAD	0
	ERZ-CF2MK201 Panasonic	VARISTOR 200V 200A 2SMD JLEAD	0
	EZJ-ZSV270TAM Panasonic	VARISTOR ARRAY 27V 43PF 0505	0
	EZJ-ZSV270EAK Panasonic	VARISTOR ARRAY 27V 47PF 0504	0
	EZJ-ZSV270PAM Panasonic	VARISTOR ARRAY 27V 33PF 0504	0
	EZJ-ZSV270SAM Panasonic	VARISTOR ARRAY 27V 39PF 0505	0
	EZJ-ZSV270TAK Panasonic	VARISTOR ARRAY 27V 43PF 0504	0
	EZJ-ZSV270RA Panasonic	VARISTOR ARRAY 27V 20PF 0504	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