TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-U15JP541 Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-C20EK681Y Panasonic	VARISTOR 680V 8KA MODULE	18
ERZ-V14D911 Panasonic	VARISTOR 910V 5KA DISC 14MM	600
ERZ-C32EK361Y Panasonic	VARISTOR 360V 25KA MODULE	19
ERZ-V05D680 Panasonic	VARISTOR 68V 250A DISC 5MM	633
ERZ-V07D331 Panasonic	VARISTOR 330V 1.75KA DISC 7MM	37
ERZ-V05D270 Panasonic	VARISTOR 27V 250A DISC 5MM	1948
EZJ-PZV6R8GA Panasonic	VARISTOR 6.8V 5A 0201	12699
EZJ-Z0V080KA Panasonic	VARISTOR 8V 15A 0402	1366
EZJ-PZV080GA Panasonic	VARISTOR 8V 5A 0201	8280
ERZ-E05A361 Panasonic	VARISTOR 360V 1.2KA DISC 7MM	7797
ERZ-V20R511 Panasonic	VARISTOR 510V 10KA DISC 20MM	491
ERZ-V20D151 Panasonic	VARISTOR 150V 10KA DISC 20MM	5419
ERZ-VS34C511 Panasonic	VARISTOR 510V 40KA SQUARE 36MM	0
ERZ-U26JP162F Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-VF2M270 Panasonic	VARISTOR 27V 125A 2SMD JLEAD	1803
ERZ-V05D220 Panasonic	VARISTOR 22V 250A DISC 5MM	1882
EZJ-P0V120JA Panasonic	VARISTOR 12V 220PF 0402	9122
ERZ-V14D470 Panasonic	VARISTOR 47V 2KA DISC 14MM	0
ERZ-C20EK391 Panasonic	VARISTOR 390V 8KA MODULE	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