TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-E10A681CS Panasonic	VARISTOR 680V 4.5KA DISC 12.50MM	0
EZJ-Z0V220HA Panasonic	VARISTOR 22V 10A 0402	4766
ERZ-E10E201 Panasonic	VARISTOR 200V 4.5KA DISC 11.5MM	0
ERZ-U22JP112B Panasonic	DELTATRANSIENT/SURGE ABSORBERS10	1
ERZ-VS34C471 Panasonic	VARISTOR 470V 40KA SQUARE 36MM	4
ERZ-E08A561 Panasonic	VARISTOR 560V 3.5KA DISC 10.5MM	1766
ERZ-E11A112CS Panasonic	VARISTOR 1.1KV 5KA DISC 13MM	0
ERZ-E10A201CS Panasonic	VARISTOR 200V 4.5KA DISC 11.5MM	0
ERZ-E10A271 Panasonic	VARISTOR 270V 4.5KA DISC 11.5MM	393
ERZ-U13JP511B Panasonic	DELTATRANSIENT/SURGE ABSORBERS10	1
EZJ-Z0V80015D Panasonic	VARISTOR 80V 0402	12665
EZJ-Z0V120JA Panasonic	VARISTOR 12V 10A 0402	38316
ERZ-E14A561S1 Panasonic	VARISTOR DISC 14MM 560V	899
ERZ-E08A331CS Panasonic	VARISTOR 330V 3.5KA DISC 10.5MM	0
EZJ-P1V650DM Panasonic	VARISTOR 65V 2A 0603	6721
ERZ-VS34C621 Panasonic	VARISTOR 620V 40KA SQUARE 36MM	5
ERZ-V20D560 Panasonic	VARISTOR 56V 3KA DISC 20MM	2227
ERZ-E14A361 Panasonic	VARISTOR 360V 10KA DISC 16.5MM	0
ERZ-C20EK911Y Panasonic	VARISTOR 910V 8KA MODULE	18
ERZ-E10F391 Panasonic	VARISTOR 390V 4.5KA DISC 11.5MM	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