TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-E10E431 Panasonic	VARISTOR 430V 4.5KA DISC 11.5MM	0
ERZ-V05D201 Panasonic	VARISTOR 200V 800A DISC 5MM	2208
ERZ-V05D431 Panasonic	VARISTOR 430V 800A DISC 5MM	0
ERZ-C20EK431Y Panasonic	VARISTOR 430V 8KA MODULE	0
ERZ-C32CK431W Panasonic	VARISTOR 430V 25KA DISC 32MM	0
ERZ-V14D511 Panasonic	VARISTOR 510V 6KA DISC 14MM	2
ERZ-U26JP102 Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-E10F561 Panasonic	VARISTOR 560V 4.5KA DISC 11.5MM	0
ERZ-E07A431CS Panasonic	VARISTOR 430V 2.5KA DISC 9MM	0
ERZ-V20R241 Panasonic	VARISTOR 240V 10KA DISC 20MM	1138
ERZ-E10B911CS Panasonic	VARISTOR 910V 4.5KA DISC 12.50MM	0
ERZ-V20D180 Panasonic	VARISTOR 18V 3KA DISC 20MM	646
ERZ-V14D821 Panasonic	VARISTOR 820V 5KA DISC 14MM	58
ERZ-V05D391 Panasonic	VARISTOR 390V 800A DISC 5MM	44101
ERZ-V10D241 Panasonic	VARISTOR 240V 3.5KA DISC 10MM	0
ERZ-E10F361 Panasonic	VARISTOR 360V 4.5KA DISC 11.5MM	0
EZJ-Z1V220JA Panasonic	VARISTOR 22V 20A 0603	4051
ERZ-U21JP192H Panasonic	DELTATRANSIENT/SURGE ABSORBERS10	1
ERZ-E10B221CS Panasonic	VARISTOR 220V 4.5KA DISC 11.5MM	0
ERZ-V07D471 Panasonic	VARISTOR 470V 1.75KA DISC 7MM	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