TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-E14A391 Panasonic	VARISTOR 390V 10KA DISC 16.5MM	2288
FBMOV460M Wickmann / Littelfuse	VARISTOR 750V 40KA AXIAL CYLINDR	0
MLESD12A-0402-TP Micro Commercial Components (MCC)	VARISTOR 0402	33767
B72210S1140K102 TDK EPCOS	VARISTOR 22V 500A DISC 10MM	689
AMCV-1206H-120-T Abracon	VARISTOR 16V 300A 1206	0
VCAS06AP303R3LAT1A Elco (AVX)	VARISTOR 120V 3A 0603	3348
VCAS040205X150WP Elco (AVX)	VARISTOR 8.5V 20A 0402	0
AVRM0603C120MT101N TDK Corporation	VARISTOR 12V 5A 0201	15827
ERZ-E14A102 Panasonic	VARISTOR 1KV 7.5KA DISC 16.5MM	0
V680LA10PX2855 Wickmann / Littelfuse	VARISTOR 1.1KV 2.5KA DISC 10MM	0
B72580V3140S272 TDK EPCOS	VARISTOR 22V 800A 1812	0
V330MA2A Wickmann / Littelfuse	VARISTOR 330V 100A SOD83A AXIAL	0
V07E250PL2T Wickmann / Littelfuse	VARISTOR 390V 1.75KA DISC 7MM	0
B72220T2271K101 TDK EPCOS	VARISTOR 430V 10KA RADIAL BOX	0
AMCV-1812H-101-T Abracon	VARISTOR 120V 600A 1812	0
820544611 Würth Elektronik Midcom	DISK VARISTOR STANDARD 14MM; 460	0
B72205S0600K101 TDK EPCOS	VARISTOR 100V 400A DISC 5MM	0
V05P35P Wickmann / Littelfuse	VARISTOR 56V 500A DISC 5MM	0
CVQ300K23BL1 J.W. Miller / Bourns	CVQ 300VRMS 23MM BULK L1	0
V5.5MLA1206NT Wickmann / Littelfuse	VARISTOR 8.2V 150A 1206	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