TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-E05A221 Panasonic	VARISTOR 220V 1.2KA DISC 7MM	321
ERZ-E10E681 Panasonic	VARISTOR 680V 4.5KA DISC 12.50MM	0
ERZ-U11JP541 Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-E10A201 Panasonic	VARISTOR 200V 4.5KA DISC 11.5MM	2030
ERZ-V07D391 Panasonic	VARISTOR 390V 1.75KA DISC 7MM	675
ERZ-U21JP132F Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-E10A431CS Panasonic	VARISTOR 430V 4.5KA DISC 11.5MM	0
ERZ-E14A331S1 Panasonic	VARISTOR DISC 14MM 330V	1945
ERZ-V10D271 Panasonic	VARISTOR 270V 3.5KA DISC 10MM	301
ERZ-E05A201 Panasonic	VARISTOR 200V 1.2KA DISC 7MM	0
ERZ-VF2M151 Panasonic	VARISTOR 150V 600A 2SMD JLEAD	4
ERZ-V10D220CS Panasonic	VARISTOR 22V 1KA DISC 10MM	0
EZJ-P0V080DA Panasonic	VARISTOR 8V 27PF 0402	68650
ERZ-U21JP112 Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-E10A821 Panasonic	VARISTOR 820V 4.5KA DISC 12.50MM	1
ERZ-C32EK241 Panasonic	VARISTOR 240V 25KA MODULE	63
ERZ-U22JP102B Panasonic	DELTATRANSIENT/SURGE ABSORBERS10	1
ERZ-E10B511CS Panasonic	VARISTOR 510V 4.5KA DISC 11.5MM	0
EZJ-S2VB223 Panasonic	VARISTOR 12V 0805	70
ERZ-V14D220 Panasonic	VARISTOR 22V 2KA 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