TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-E10F221 Panasonic	VARISTOR 220V 4.5KA DISC 11.5MM	0
ERZ-HF2M270 Panasonic	VARISTOR 27V SMD TYPE	14
ERZ-C32EK112Y Panasonic	VARISTOR 1.1KV 25KA MODULE	2
ERZ-E07A431 Panasonic	VARISTOR 430V 2.5KA DISC 9MM	0
ERZ-U25JP192F Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-V20R391 Panasonic	VARISTOR 390V 10KA DISC 20MM	569
ERZ-VF2M680 Panasonic	VARISTOR 68V 125A 2SMD JLEAD	939
ERZ-E05A201CS Panasonic	VARISTOR 200V 1.2KA DISC 7MM	0
ERZ-E11A751CS Panasonic	VARISTOR 750V 5KA DISC 14MM	0
EZJ-S1VB822 Panasonic	VARISTOR 12V 0603	33066
ERZ-E11A471 Panasonic	VARISTOR 470V 6KA DISC 13MM	2354
ERZ-VF2M820 Panasonic	VARISTOR 82V 600A 2SMD JLEAD	28125
ERZ-V05D390 Panasonic	VARISTOR 39V 250A DISC 5MM	9718
ERZ-E10A361CS Panasonic	VARISTOR 360V 4.5KA DISC 11.5MM	0
ERZ-U24JP162F Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-E08A751CS Panasonic	VARISTOR 750V 3.5KA DISC 11.5MM	0
ERZ-E11A561CS Panasonic	VARISTOR 560V 6KA DISC 13MM	0
ERZ-E10B331CS Panasonic	VARISTOR 330V 4.5KA DISC 11.5MM	0
ERZ-V05D361 Panasonic	VARISTOR 360V 800A DISC 5MM	4432
ERZ-E14A221S1 Panasonic	VARISTOR DISC 14MM 220V	1951

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