TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-C40CK241W Panasonic	VARISTOR 240V 30KA DISC 40MM	49
ERZ-E07A391 Panasonic	VARISTOR 390V 2.5KA DISC 9MM	976
ERZ-V14D681 Panasonic	VARISTOR 680V 5KA DISC 14MM	40490
ERZ-C32EK751Y Panasonic	VARISTOR 750V 25KA MODULE	11
ERZ-E07A271 Panasonic	VARISTOR 270V 2.5KA DISC 9MM	2893
ERZ-E10F271 Panasonic	VARISTOR 270V 4.5KA DISC 11.5MM	0
ERZ-U21JP102B Panasonic	DELTATRANSIENT/SURGE ABSORBERS10	1
ERZ-E10B271CS Panasonic	VARISTOR 270V 4.5KA DISC 11.5MM	0
ERZ-U24JP222F Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-U16JP541 Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
ERZ-E10A241 Panasonic	VARISTOR 240V 4.5KA DISC 11.5MM	0
ERZ-E05A241 Panasonic	VARISTOR 240V 1.2KA DISC 7MM	465
ERZ-C20EK112Y Panasonic	VARISTOR 1.1KV 8KA MODULE	0
ERZ-C32EK241Y Panasonic	VARISTOR 240V 25KA MODULE	36
ERZ-E14A201 Panasonic	VARISTOR 200V 10KA DISC 16.5MM	0
ERZ-E14A911S1 Panasonic	VARISTOR DISC 14MM 910V	0
EZJ-Z1V650DM Panasonic	VARISTOR 65V 5A 0603	1089
EZA-EG1A50AC Panasonic	ESD SUPPRESSOR 0201	21061
ERZ-C32CK821W Panasonic	VARISTOR 820V 25KA DISC 32MM	304
ERZ-E08A331 Panasonic	VARISTOR 330V 3.5KA DISC 10.5MM	429

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