TVS - Varistors, MOVs

Image	Part Number	Description / PDF	Quantity	Rfq
	ERZ-E07B431CS Panasonic	VARISTOR 430V 2.5KA DISC 9MM	0
	ERZ-VA5V201 Panasonic	VARISTOR 200V 800A DISC 5MM	0
	ERZ-E08B331CS Panasonic	VARISTOR 330V 3.5KA DISC 10.5MM	0
	ERZ-E14A431SC Panasonic	VARISTOR DISC 14MM 430V	0
	ERZ-E11B911CS Panasonic	VARISTOR 910V 5KA DISC 14MM	0
	ERZ-E14A681SC Panasonic	VARISTOR DISC 14MM 680V	0
	ERZ-E11E621 Panasonic	VARISTOR 620V 5KA DISC 14MM	0
	ERZ-E11E102 Panasonic	VARISTOR 1KV 5KA DISC 13MM	0
	ERZ-E05E431 Panasonic	VARISTOR 430V 1.2KA DISC 7MM	0
	ERZ-E14A561SC Panasonic	VARISTOR DISC 14MM 560V	0
	ERZ-E08E331 Panasonic	VARISTOR 330V 3.5KA DISC 10.5MM	0
	ERZ-E11B511CS Panasonic	VARISTOR 510V 6KA DISC 13MM	0
	ERZ-E14A331SC Panasonic	VARISTOR DISC 14MM 330V	0
	ERZ-E14A511SC Panasonic	VARISTOR DISC 14MM 510V	0
	ERZ-VA5V560 Panasonic	VARISTOR 56V 250A DISC 5MM	0
	ERZ-V07V680CS Panasonic	VARISTOR 68V 500A DISC 7MM	0
	ERZ-E08F621 Panasonic	VARISTOR 620V 3.5KA DISC 11.5MM	0
	ERZ-E14A271SC Panasonic	VARISTOR DISC 14MM 270V	0
	ERZ-E08E511 Panasonic	VARISTOR 510V 3.5KA DISC 10.5MM	0
	ERZ-E08B621CS Panasonic	VARISTOR 620V 3.5KA DISC 11.5MM	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