TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-E10A621 Panasonic	VARISTOR 620V 4.5KA DISC 12.50MM	0
ERZ-V07V221CS Panasonic	VARISTOR 220V 1.75KA DISC 7MM	0
ERZ-V07D431 Panasonic	VARISTOR 430V 1.75KA DISC 7MM	0
ERZ-E10A102 Panasonic	VARISTOR 1KV 4.5KA DISC 12.50MM	1562
ERZ-VF2M470 Panasonic	VARISTOR 47V 125A 2SMD JLEAD	1605
ERZ-E10B561CS Panasonic	VARISTOR 560V 4.5KA DISC 11.5MM	0
ERZ-V05D101 Panasonic	VARISTOR 100V 800A DISC 5MM	4
ERZ-VF2M201 Panasonic	VARISTOR 200V 600A 2SMD JLEAD	405
ERZ-C32EK471Y Panasonic	VARISTOR 470V 25KA MODULE	18
ERZ-E10A911 Panasonic	VARISTOR 910V 4.5KA DISC 12.50MM	553
ERZ-E14A331 Panasonic	VARISTOR 330V 10KA DISC 16.5MM	97
ERZ-E08A621CS Panasonic	VARISTOR 620V 3.5KA DISC 11.5MM	0
ERZ-V20D361 Panasonic	VARISTOR 360V 10KA DISC 21.5MM	111700
ERZ-E10A271CS Panasonic	VARISTOR 270V 4.5KA DISC 11.5MM	0
ERZ-VA7V680 Panasonic	VARISTOR 68V 500A DISC 7MM	45069
ERZ-E07A241CS Panasonic	VARISTOR 240V 2.5KA DISC 9MM	0
ERZ-E05A271 Panasonic	VARISTOR 270V 1.2KA DISC 7MM	9922
ERZ-V14D390 Panasonic	VARISTOR 39V 2KA DISC 14MM	12395
ERZ-E10B201CS Panasonic	VARISTOR 200V 4.5KA DISC 11.5MM	0
ERZ-V14D361 Panasonic	VARISTOR 360V 6KA DISC 14MM	335

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