TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
VDRS10D040BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 68V 500A DISC 12MM	0
VDRUS10T175BKE Vishay BC Components/Beyshlag/Draloric	VDR US 10D 4500A 175V KNLDS	0
VDRUS20Z550BKE Vishay BC Components/Beyshlag/Draloric	VDR US 20D 130AA 550V KNLDS	0
VDRH14V320BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 510V 6KA DISC 16MM	0
VDRUS10T140BKE Vishay BC Components/Beyshlag/Draloric	VDR US 10D 4500A 140V KNLDS	0
VDRS05C385BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 620V 400A DISC 7MM	0
VDRS05A017TSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 27V 100A DISC 7MM	0
MLV0603E31403T Vishay BC Components/Beyshlag/Draloric	VARISTOR 25.5V 30A 0603	731
VDRUS10T175BSE Vishay BC Components/Beyshlag/Draloric	VDR US 10D 4500A 175V STLDS BULK	1862
VDRUS14X175BSE Vishay BC Components/Beyshlag/Draloric	VDR US 14D 8000A 175V STLDS BULK	954
VDRS14T320BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 510V 4.5KA DISC 16MM	0
VDRS20W680BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 1.1KV 6.5KA DISC 23MM	0
VDRS10P350TSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 560V 2.5KA DISC 12.50MM	0
VDRS14T250BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 390V 4.5KA DISC 16MM	806
VDRS10P130BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 205V 2.5KA DISC 12MM	2165
MLV0402E30703T Vishay BC Components/Beyshlag/Draloric	VARISTOR 12.5V 20A 0402	3886
VDRS14T130BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 205V 4.5KA DISC 16MM	0
VDRS10P385BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 620V 2.5KA DISC 12.50MM	0
VDRUS14X230BKE Vishay BC Components/Beyshlag/Draloric	VDR US 14D 8000A 230V KNLDS	0
VDRS10D025TSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 39V 500A DISC 12MM	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