TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-V20D330 Panasonic	VARISTOR 33V 3KA DISC 20MM	0
B72210S0350K551 TDK EPCOS	VARISTOR 56V 500A DISC 10MM	0
ZV60K2220801NIR1 J.W. Miller / Bourns	VARISTOR SMD	995
MOV-07D681KTR J.W. Miller / Bourns	VARISTOR 680V 1.2KA DISC 7MM	297
NTE2V060 NTE Electronics, Inc.	MOV 60V RMS	564
B72214S0421K101 TDK EPCOS	VARISTOR 680V 4.5KA DISC 14MM	2675
VE1812K401R060 KEMET	VARISTOR 100V 400A 1812	0
MOV-14D391KTR J.W. Miller / Bourns	VARISTOR 390V 4.5KA DISC 14MM	4744
AV14K2220122NIR1HT J.W. Miller / Bourns	VARISTOR	990
82541140 Würth Elektronik Midcom	VARISTOR 24V 200A 1206	474
V200CH8T Wickmann / Littelfuse	VARISTOR 200V 250A 2SMD NO LEAD	5800
TMOV20RP510E Wickmann / Littelfuse	VARISTOR 820V 10KA DISC 20MM	1844
B72500T0040M060 TDK EPCOS	VARISTOR 8V 30A 0603	9023
MVR07D330K Meritek	VARISTOR 33V 250A 7MM DISC THRU	0
ERZ-E11A241CS Panasonic	VARISTOR 240V 6KA DISC 13MM	0
B72205S0600K311 TDK EPCOS	VARISTOR 100V 400A DISC 5MM	0
TMOV14RP275EL2T7 Wickmann / Littelfuse	VARISTOR 430V 6KA DISC 14MM	0
V9MLA0805LNA Wickmann / Littelfuse	VARISTOR 13.5V 40A 0805	0
V07E275PL4B5 Wickmann / Littelfuse	VARISTOR 430V 1.75KA DISC 7MM	0
V07E130PL3T Wickmann / Littelfuse	VARISTOR 205V 1.75KA 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