TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
VDRS05C320BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 510V 400A DISC 7MM	0
VDRS20W420BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 680V 6.5KA DISC 23MM	0
VDRUS07M230BSE Vishay BC Components/Beyshlag/Draloric	VDR US 07D 1800A 230V STLDS BULK	1963
VDRS05C050BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 82V 400A DISC 7MM	0
VDRS20W385BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 620V 6.5KA DISC 23MM	0
VDRUS20Z625BKE Vishay BC Components/Beyshlag/Draloric	VDR US 20D 130AA 625V KNLDS	0
VDRUS20Z320BKE Vishay BC Components/Beyshlag/Draloric	VDR US 20D 130AA 320V KNLDS	0
VDRS14G035BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 56V 1KA DISC 16MM	0
VDRS05C095BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 150V 400A DISC 7MM	0
VDRUS07M150BSE Vishay BC Components/Beyshlag/Draloric	VDR US 07D 1800A 150V STLDS BULK	1748
MLV0805E30403T Vishay BC Components/Beyshlag/Draloric	VARISTOR 8.2V 40A 0805	1751
VDRS14T275TSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 430V 4.5KA DISC 16MM	92
VDRS10P095BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 150V 2.5KA DISC 12MM	0
VDRUS10T130BKE Vishay BC Components/Beyshlag/Draloric	VDR US 10D 4500A 130V KNLDS	0
VDRUS20Z250BSE Vishay BC Components/Beyshlag/Draloric	VDR US 20D 130AA 250V STLDS BULK	435
VDRUS10T150BSE Vishay BC Components/Beyshlag/Draloric	VDR US 10D 4500A 150V STLDS	0
VDRS07H250BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 390V 1.2KA DISC 9MM	578
MLV0805E31305T Vishay BC Components/Beyshlag/Draloric	MLV SMD 0805 NISN 13V TAPE E3	0
VDRS20W075BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 120V 6.5KA DISC 22.50MM	0
VDRS20M025BSE Vishay BC Components/Beyshlag/Draloric	VARISTOR 39V 2KA DISC 22.50MM	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