TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-V07D511 Panasonic	VARISTOR 510V 1.75KA DISC 7MM	22040
ERZ-E07A361CS Panasonic	VARISTOR 360V 2.5KA DISC 9MM	0
ERZ-V20R361 Panasonic	VARISTOR 360V 10KA DISC 20MM	6488
ERZ-C20EK241Y Panasonic	VARISTOR 240V 8KA MODULE	15
ERZ-E11A471CS Panasonic	VARISTOR 470V 6KA DISC 13MM	0
EZJ-PZV6R8JA Panasonic	VARISTOR 6.8V 5A 0201	2925
ERZ-U14JP511B Panasonic	DELTATRANSIENT/SURGE ABSORBERS10	1
ERZ-E11A331 Panasonic	VARISTOR 330V 6KA DISC 13MM	2812
ERZ-V20D201 Panasonic	VARISTOR 200V 10KA DISC 20MM	3316
ERZ-C32EK781Y Panasonic	VARISTOR 780V 25KA MODULE	6
ERZ-U24JP102 Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
EZJ-PZV150RA Panasonic	VARISTOR 15V 1A 0201	27286
ERZ-V20D220 Panasonic	VARISTOR 22V 3KA DISC 20MM	0
EZJ-P0V220HM Panasonic	VARISTOR 22V 0402	9585
ERZ-E10A911CS Panasonic	VARISTOR 910V 4.5KA DISC 12.50MM	0
ERZ-E08A391 Panasonic	VARISTOR 390V 3.5KA DISC 10.5MM	985
ERZ-E08A511 Panasonic	VARISTOR 510V 3.5KA DISC 10.5MM	799
ERZ-V05D820 Panasonic	VARISTOR 82V 800A DISC 5MM	36830
ERZ-E10F821 Panasonic	VARISTOR 820V 4.5KA DISC 12.50MM	0
ERZ-E10A561CS Panasonic	VARISTOR 560V 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