TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-V05D180 Panasonic	VARISTOR 18V 250A DISC 5MM	4789
ERZ-E10B361CS Panasonic	VARISTOR 360V 4.5KA DISC 11.5MM	0
ERZ-E14A561 Panasonic	VARISTOR 560V 10KA DISC 16.5MM	325
EZJ-Z1V330GA Panasonic	VARISTOR 33V 20A 0603	9049
ERZ-V20D391 Panasonic	VARISTOR 390V 10KA DISC 20MM	31014
ERZ-E10F751 Panasonic	VARISTOR 750V 4.5KA DISC 12.50MM	0
EZA-EG2N50AX Panasonic	ESD SUPPRESSOR 0402	52278
ERZ-C32EK621Y Panasonic	VARISTOR 620V 25KA MODULE	12
ERZ-E14A271 Panasonic	VARISTOR 270V 10KA DISC 16.5MM	0
ERZ-U24JP192F Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
EZJ-P1V270EM Panasonic	VARISTOR 27V 5A 0603	3484
ERZ-C32EK201Y Panasonic	VARISTOR 200V 25KA MODULE	4
ERZ-V10D560 Panasonic	VARISTOR 56V 1KA DISC 10MM	0
EZJ-P0V270RM Panasonic	VARISTOR 27V 1A 0402	8627
ERZ-E07A621 Panasonic	VARISTOR 620V 2.5KA DISC 9MM	3272
ERZ-E07A331 Panasonic	VARISTOR 330V 2.5KA DISC 9MM	895
ERZ-E14A391 Panasonic	VARISTOR 390V 10KA DISC 16.5MM	2288
ERZ-E14A102 Panasonic	VARISTOR 1KV 7.5KA DISC 16.5MM	0
EZJ-P0V120JM Panasonic	VARISTOR 12V 10A 0402	10000
ERZ-V10D751 Panasonic	VARISTOR 750V 3.5KA DISC 10MM	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