TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
B72540T6500S162 TDK EPCOS	VARISTOR 77.5V 4.5KA 2220	1383
ZV35K1812601NIR1 J.W. Miller / Bourns	VARISTOR SMD	1000
B72220S0400K101 TDK EPCOS	VARISTOR 68V 2KA DISC 20MM	36364
B72207S0211K101 TDK EPCOS	VARISTOR DISC 7MM	0
B72650M0151K072 TDK EPCOS	VARISTOR 240V 400A 2SMD JLEAD	30807
DV140K4032R2 J.W. Miller / Bourns	DV SERIES 140V 4032 PKG SMD VARI	0
VR15AT18A650R Elco (AVX)	VARISTOR 41V 30A RADIAL	13
820574211 Würth Elektronik Midcom	DISK VARISTOR STANDARD WE-VD 7MM	0
B72214U2511K501 TDK EPCOS	VARISTOR 820V 5KA DISC 14MM	300
ERZ-V10D182 Panasonic	VARISTOR 1.8KV 3.5KA DISC 10MM	0
V240ZA05P Wickmann / Littelfuse	VARISTOR 240V 400A DISC 5MM	0
ERZ-E10E561 Panasonic	VARISTOR 560V 4.5KA DISC 11.5MM	0
AVR-M1005C180MTAAB TDK Corporation	VARISTOR 18V 16A 0402	5187
B72207S0381K101 TDK EPCOS	VARISTOR 620V 1.2KA DISC 7MM	10433
MVR10D330K Meritek	VARISTOR 33V 500A 10MM DISC THRU	0
PV60K4032R2 J.W. Miller / Bourns	PV SERIES 60V 4032 PKG	1000
MVR07D151K Meritek	VARISTOR 150V 1200A 7MM DISC THR	0
VCAS120634N770DP Elco (AVX)	VARISTOR 47V 200A 1206	1000
B72210S2131K101 TDK EPCOS	VARISTOR 205V 3.5KA DISC 10MM	3222
V150LT5CP Wickmann / Littelfuse	VARISTOR 240V 3.5KA DISC 10MM	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