TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
MVR10D361K Meritek	VARISTOR 360V 2500A 10MM DISC TH	0
V275LA10CPX2855 Wickmann / Littelfuse	VARISTOR 430V 3.5KA DISC 10MM	0
EZJ-S2VB223 Panasonic	VARISTOR 12V 0805	70
V300LU40CPX2855 Wickmann / Littelfuse	VARISTOR 470V 10KA DISC 20MM	0
VA100026D580DL Elco (AVX)	VARISTOR 34.5V 120A AXIAL	47
CGA0603MLC-05E J.W. Miller / Bourns	VARISTOR 0603	2
82536070 Würth Elektronik Midcom	VARISTOR 13.5V 30A 0603	2356
ERZ-V14D220 Panasonic	VARISTOR 22V 2KA DISC 14MM	0
VC080514A300DP Elco (AVX)	VARISTOR 18.5V 40A 0805	1000
DV115K4032R2 J.W. Miller / Bourns	DV SERIES 115V 4032 PKG SMD VARI	0
B72220S0750K101 TDK EPCOS	VARISTOR 120V 6.5KA DISC 20MM	293
V47ZS1PX1347 Wickmann / Littelfuse	VARISTOR 47V 250A DISC 7MM	0
VC120638N770RP Elco (AVX)	VARISTOR 47V 200A 1206	3390
V68MA3A Wickmann / Littelfuse	VARISTOR 68V 40A SOD83A AXIAL	0
AMCV-1812H-120-T Abracon	VARISTOR 16V 800A 1812	0
VC12LC18A500DP Elco (AVX)	VARISTOR 30A 1206	3000
V275LC10P Wickmann / Littelfuse	VARISTOR 430V 2.5KA DISC 10MM	0
V240CH8S Wickmann / Littelfuse	VARISTOR 240V 250A 2SMD NO LEAD	0
AMCV-1206H-750-T Abracon	VARISTOR 94V 250A 1206	0
V180ZT1P Wickmann / Littelfuse	VARISTOR 180V 1.2KA DISC 7MM	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