TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-E10A201 Panasonic	VARISTOR 200V 4.5KA DISC 11.5MM	2030
V10H175P Wickmann / Littelfuse	VARISTOR 270V 3.5KA DISC 10MM	0
V460LA7P Wickmann / Littelfuse	VARISTOR 715V 1.2KA DISC 7MM	0
B72660M0500K093 TDK EPCOS	VARISTOR 82V 1.2KA 4032	0
VDRUS10T300BKE Vishay BC Components/Beyshlag/Draloric	VDR US 10D 4500A 300V KNLDS	0
ERZ-V07D391 Panasonic	VARISTOR 390V 1.75KA DISC 7MM	675
V150LT1P Wickmann / Littelfuse	VARISTOR 250V 1.2KA DISC 7MM	0
TMOV14RP130E Wickmann / Littelfuse	VARISTOR 205V 6KA DISC 14MM	600
V510LA80B	VARISTOR 68V 1.2KA 32SOIC	196
B72205S0171K111 TDK EPCOS	VARISTOR 270V 400A DISC 5MM	5702
V18MLE0805LH Wickmann / Littelfuse	VARISTOR 25V 0805	8851
V39CH8S Wickmann / Littelfuse	VARISTOR 39V 100A 2SMD NO LEAD	0
B72205S0301K101 TDK EPCOS	VARISTOR 470V 400A DISC 5MM	6426
B72220S0321K101 TDK EPCOS	VARISTOR 510V 8KA DISC 20MM	551
TMOV14RP275EL3T7 Wickmann / Littelfuse	VARISTOR 430V 6KA DISC 14MM	0
B72520T0300K072 TDK EPCOS	VARISTOR 47V 200A 1206	0
ERZ-U21JP132F Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	1
V550LU80CP Wickmann / Littelfuse	VARISTOR 880V 10KA DISC 20MM	0
VGAS181218P440DP Elco (AVX)	VARISTOR 27.5V 800A 1812	0
MVR05D751K Meritek	VARISTOR 750V 400A 5MM DISC THRU	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