TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
EZJ-Z1V330GM Panasonic	VARISTOR 33V 20A 0603	7947
ERZ-V10D431 Panasonic	VARISTOR 430V 3.5KA DISC 10MM	0
ERZ-E11A821CS Panasonic	VARISTOR 820V 5KA DISC 14MM	0
ERZ-E11A201CS Panasonic	VARISTOR 200V 6KA DISC 13MM	0
ERZ-C40CK681W Panasonic	VARISTOR 680V 30KA DISC 40MM	297
ERZ-E08A271CS Panasonic	VARISTOR 270V 3.5KA DISC 10.5MM	0
EZJ-ZSV270EA Panasonic	VARISTOR 27V 5A 0504	23
ERZ-V20R471 Panasonic	VARISTOR 470V 10KA DISC 20MM	335
ERZ-V07D390 Panasonic	VARISTOR 39V 500A DISC 7MM	16228
ERZ-E14A241 Panasonic	VARISTOR 240V 10KA DISC 16.5MM	3326
ERZ-V10D390 Panasonic	VARISTOR 39V 1KA DISC 10MM	6116
ERZ-E14A431 Panasonic	VARISTOR 430V 10KA DISC 16.5MM	0
EZJ-Z1V180JM Panasonic	VARISTOR 18V 20A 0603	7820
ERZ-C20EK201 Panasonic	VARISTOR 200V 8KA MODULE	0
ERZ-E10B471CS Panasonic	VARISTOR 470V 4.5KA DISC 11.5MM	0
ERZ-E08A201 Panasonic	VARISTOR 200V 3.5KA DISC 10.5MM	152
ERZ-E10E621 Panasonic	VARISTOR 620V 4.5KA DISC 12.50MM	0
EZJ-Z0V171AA Panasonic	VARISTOR 170V 0402	5004
ERZ-VF2M471 Panasonic	VARISTOR 470V 300A 2SMD JLEAD	3465
ERZ-V14D102 Panasonic	VARISTOR 1KV 5KA DISC 14MM	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