TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
V07E275PL4B5 Wickmann / Littelfuse	VARISTOR 430V 1.75KA DISC 7MM	0
V07E130PL3T Wickmann / Littelfuse	VARISTOR 205V 1.75KA DISC 7MM	0
V150LT20BP Wickmann / Littelfuse	VARISTOR 229.5V 6.5KA DISC 20MM	0
V18ZT2P Wickmann / Littelfuse	VARISTOR 18V 500A DISC 10MM	0
V82MA3A Wickmann / Littelfuse	VARISTOR 82V 40A SOD83A AXIAL	0
V130LA10APX1347 Wickmann / Littelfuse	VARISTOR 205V 4.5KA DISC 14MM	0
V10E175P Wickmann / Littelfuse	VARISTOR 270V 3.5KA DISC 10MM	0
V250LU40CPX2855 Wickmann / Littelfuse	VARISTOR 390V 10KA DISC 20MM	0
V56ZS20PX10 Wickmann / Littelfuse	VARISTOR 56V 2KA DISC 20MM	0
TMOV34S321EP Wickmann / Littelfuse	VARISTOR 510V 40KA SQUARE 34MM	0
V250LA40CPX620 Wickmann / Littelfuse	VARISTOR 383.5V 10KA DISC 20MM	3392
V510LS80BP Wickmann / Littelfuse	VARISTOR 799V 6.5KA DISC 20MM	0
V625LC80CPX2855 Wickmann / Littelfuse	VARISTOR 1KV 10KA DISC 20MM	0
V39ZC1P Wickmann / Littelfuse	VARISTOR 39V 250A DISC 7MM	0
V625LU80CPX2855 Wickmann / Littelfuse	VARISTOR 1KV 10KA DISC 20MM	0
V36RA22X2749 Wickmann / Littelfuse	VARISTOR 36V 2KA RADIAL BOX	0
V680LA100CPX2855 Wickmann / Littelfuse	VARISTOR 1.06KV 10KA DISC 20MM	0
V12ZS1P Wickmann / Littelfuse	VARISTOR 12.5V 100A DISC 7MM	0
V320LA7P Wickmann / Littelfuse	VARISTOR 510V 1.2KA DISC 7MM	312
V18MLE0603H Wickmann / Littelfuse	VARISTOR 25V 0603	3746

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