TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
V30MLA1210LNHAUTO Wickmann / Littelfuse	VARISTOR 39V 220A 1210	0
TMOV34S751MP Wickmann / Littelfuse	VARISTOR 1.2KV 40KA SQUARE 34MM	0
V230LS10CPX2855 Wickmann / Littelfuse	VARISTOR 360V 3.5KA DISC 10MM	0
V20P30P Wickmann / Littelfuse	VARISTOR 47V 8KA DISC 20MM	1056
V420LU40CPX10 Wickmann / Littelfuse	VARISTOR 680V 10KA DISC 20MM	0
V07E250P Wickmann / Littelfuse	VARISTOR 390V 1.75KA DISC 7MM	4317
TMOV25SP150E Wickmann / Littelfuse	VARISTOR 240V 20KA SQUARE 28MM	0
V10P17PL1T7 Wickmann / Littelfuse	VARISTOR 27V 2KA DISC 10MM	0
V250SM20 Wickmann / Littelfuse	VARISTOR 391.5V 6.5KA DISC 20MM	0
V12MLA0805LH Wickmann / Littelfuse	VARISTOR 16.25V 40A 0805	83
V220MT4B Wickmann / Littelfuse	VARISTOR 220V 100A SOD83A AXIAL	0
V251HF34 Wickmann / Littelfuse	VARISTOR 390V 40KA SQUARE 34MM	0
V680LA10CP Wickmann / Littelfuse	VARISTOR 1.1KV 3.5KA DISC 10MM	0
V150LS10AP Wickmann / Littelfuse	VARISTOR 240V 4.5KA DISC 14MM	0
V120MA2B Wickmann / Littelfuse	VARISTOR 120V 100A SOD83A AXIAL	0
V14E20PL1T Wickmann / Littelfuse	RAD VARISTOR 14MM	0
V300LT10CP Wickmann / Littelfuse	VARISTOR 470V 3.5KA DISC 10MM	0
V140LS20CPX10 Wickmann / Littelfuse	VARISTOR 220V 10KA DISC 20MM	0
V150LS5P Wickmann / Littelfuse	VARISTOR 240V 2.5KA DISC 10MM	0
V390MA3A Wickmann / Littelfuse	VARISTOR 390V 100A 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