TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
V390MA6B Wickmann / Littelfuse	VARISTOR 390V 100A SOD83A AXIAL	0
V39ZS3P Wickmann / Littelfuse	VARISTOR 39V 500A DISC 10MM	0
V18ZA3PX1347 Wickmann / Littelfuse	VARISTOR 18V 1KA DISC 14MM	0
V0402MHS03NR Wickmann / Littelfuse	VARISTOR 135V 0402	58912
V385LU40CPX2855 Wickmann / Littelfuse	VARISTOR 620V 10KA DISC 20MM	0
V10E25AUTO Wickmann / Littelfuse	VARISTOR 39V 1.5KA DISC 10MM	0
V660LS80CPX2855 Wickmann / Littelfuse	VARISTOR 1.08KV 10KA DISC 20MM	0
V300LU10CP Wickmann / Littelfuse	VARISTOR 470V 3.5KA DISC 10MM	0
V14H230P Wickmann / Littelfuse	VARISTOR 360V 6.5KA DISC 14MM	0
V130LU2P Wickmann / Littelfuse	VARISTOR 205V 1.2KA DISC 7MM	0
V68ZA2P Wickmann / Littelfuse	VARISTOR 68V 250A DISC 7MM	4943
V56ZA20P Wickmann / Littelfuse	VARISTOR 56V 2KA DISC 20MM	47
V330ZT05P Wickmann / Littelfuse	VARISTOR 340V 400A DISC 5MM	0
V320LS40CPX2855 Wickmann / Littelfuse	VARISTOR 510V 10KA DISC 20MM	0
TMOV14RP130ML2T7 Wickmann / Littelfuse	VARISTOR 205V 6KA DISC 14MM	0
V10H30P Wickmann / Littelfuse	VARISTOR 47V 1.5KA DISC 10MM	0
TMOV14RP140EL2T7 Wickmann / Littelfuse	VARISTOR 220V 6KA DISC 14MM	0
V320LS20CP Wickmann / Littelfuse	VARISTOR 510V 6.5KA DISC 14MM	0
V180MT3B Wickmann / Littelfuse	VARISTOR 180V 100A SOD83A AXIAL	0
V68MA3B Wickmann / Littelfuse	VARISTOR 68V 40A SOD83A AXIAL	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