TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
B72214T2381K101 TDK EPCOS	VARISTOR 620V 6KA 3SIP	0
B72210S0271K551 TDK EPCOS	VARISTOR 430V 2.5KA DISC 10MM	358
B72214S0231K101 TDK EPCOS	VARISTOR 360V 4.5KA DISC 14MM	478
V175LA5P Wickmann / Littelfuse	VARISTOR 270V 2.5KA DISC 10MM	9252
V120ZS1P Wickmann / Littelfuse	VARISTOR 120V 1.2KA DISC 7MM	0
V385LS40CPX10 Wickmann / Littelfuse	VARISTOR 620V 10KA DISC 20MM	0
MVR07D511K Meritek	VARISTOR 510V 1200A 7MM DISC THR	5000
V18ZT05P Wickmann / Littelfuse	VARISTOR 18V 100A DISC 5MM	0
TMOV34S661MP Wickmann / Littelfuse	VARISTOR 1.05KV 40KA SQUARE 34MM	0
EZA-EG2N50AX Panasonic	ESD SUPPRESSOR 0402	52278
CV150K20BL1 J.W. Miller / Bourns	CV 150VRMS 20MM BULK L1	0
B72500E5250L060 TDK EPCOS	VARISTOR 61V 5A 0603	0
MVR10D102K-S Meritek	VARISTOR 1000V 3500A DISC 10MM H	0
B72210S2251K101 TDK EPCOS	VARISTOR 390V 3.5KA DISC 10MM	350
ERZ-C32EK621Y Panasonic	VARISTOR 620V 25KA MODULE	12
V460LC40CP Wickmann / Littelfuse	VARISTOR 715V 10KA DISC 20MM	0
V20H385P Wickmann / Littelfuse	VARISTOR 620V 10KA DISC 20MM	0
8S17SM950 Maida Development Company	MOV SURFACE MOUNT CHIP 3220 95VA	10000
V150LC20BP Wickmann / Littelfuse	VARISTOR 229.5V 6.5KA DISC 20MM	0
V120CH8S Wickmann / Littelfuse	VARISTOR 120V 250A 2SMD NO LEAD	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