TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-V14D121 Panasonic	VARISTOR 120V 6KA DISC 14MM	28102
ERZ-V14D201 Panasonic	VARISTOR 200V 6KA DISC 14MM	9320
ERZ-V20R331 Panasonic	VARISTOR 330V 10KA DISC 20MM	167
ERZ-V20D820 Panasonic	VARISTOR 82V 10KA DISC 20MM	7882
ERZ-V10D680 Panasonic	VARISTOR 68V 1KA DISC 10MM	4000
ERZ-C40CK751W Panasonic	VARISTOR 750V 30KA DISC 40MM	105
ERZ-VS34C271 Panasonic	VARISTOR 270V 40KA SQUARE 36MM	13
ERZ-V07D220 Panasonic	VARISTOR 22V 500A DISC 7MM	0
ERZ-U11JP541B Panasonic	DELTATRANSIENT/SURGE ABSORBERS10	1
ERZ-E10F471 Panasonic	VARISTOR 470V 4.5KA DISC 11.5MM	0
EZJ-PZV270RA Panasonic	VARISTOR 27V 1A 0201	15000
ERZ-U21JP192F Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-U12JP541B Panasonic	DELTATRANSIENT/SURGE ABSORBERS10	1
ERZ-E11A271CS Panasonic	VARISTOR 270V 6KA DISC 13MM	0
ERZ-E08A361 Panasonic	VARISTOR 360V 3.5KA DISC 10.5MM	437
ERZ-VF2M121 Panasonic	VARISTOR 120V 600A 2SMD JLEAD	5432
ERZ-V20D102 Panasonic	VARISTOR 1KV 7.5KA DISC 20MM	0
ERZ-E08A471 Panasonic	VARISTOR 470V 3.5KA DISC 10.5MM	29800
ERZ-U22JP162H Panasonic	DELTATRANSIENT/SURGE ABSORBERS10	1
ERZ-U15JP511 Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1

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