TVS - Varistors, MOVs

Image Part Number Description / PDF Quantity Rfq
VA100014D300TL

VA100014D300TL

Elco (AVX)

VARISTOR LEADED

0

VCAS120618D400TP

VCAS120618D400TP

Elco (AVX)

TRANSGUARD

0

VCUG060075L1TP

VCUG060075L1TP

Elco (AVX)

TRANSGUARD

0

VCUG080150L1TP

VCUG080150L1TP

Elco (AVX)

TRANSGUARD

0

VCAS080512A250RP

VCAS080512A250RP

Elco (AVX)

TRANSGUARD

0

VC080503A100TP

VC080503A100TP

Elco (AVX)

TRANSGUARD

0

VCUG060150L1DP

VCUG060150L1DP

Elco (AVX)

TRANSGUARD

0

VCAS06AG18120YAT3A

VCAS06AG18120YAT3A

Elco (AVX)

TRANSGUARD

0

VCUG080030H1DP

VCUG080030H1DP

Elco (AVX)

TRANSGUARD

0

VCAS080509A200RP

VCAS080509A200RP

Elco (AVX)

TRANSGUARD

0

VCAS120630D650TP

VCAS120630D650TP

Elco (AVX)

TRANSGUARD

0

VCAS121030H620RP

VCAS121030H620RP

Elco (AVX)

TRANSGUARD

96000

VCUG080320L1DP

VCUG080320L1DP

Elco (AVX)

TRANSGUARD

0

MG052S05A150RP

MG052S05A150RP

Elco (AVX)

MULTIGUARD

0

VCAS08LC18A500RP

VCAS08LC18A500RP

Elco (AVX)

TRANSGUARD

0

VCUG080075H1DP

VCUG080075H1DP

Elco (AVX)

TRANSGUARD

0

VC080538C770RP

VC080538C770RP

Elco (AVX)

TRANSGUARD

0

VCAS060309A200RP

VCAS060309A200RP

Elco (AVX)

TRANSGUARD

0

VC080526A580TP

VC080526A580TP

Elco (AVX)

TRANSGUARD

0

VCAS080518A400DP

VCAS080518A400DP

Elco (AVX)

TRANSGUARD

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

TypeFunctional CharacteristicsApplication Examples
TVS DiodesUnidirectional/bidirectional clamping, sub-nanosecond response time, low leakage currentCommunication interfaces (USB, HDMI), microcontrollers, power supplies
Zinc Oxide VaristorsHigh energy absorption, voltage-dependent resistance, aging characteristicsPower line protection, industrial motor drives, surge protection strips
MOVsSpecialized varistors with metal oxide ceramics, optimized for AC/DC applicationsAppliances, 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

ParameterDescriptionImportance
Clamping Voltage (VCLAMP)Voltage level during surge conductionDetermines protection level for downstream components
Response TimeTime to transition from blocking to clamping modeTVS: 0.5-10 ns; MOVs: 10-50 ns
Energy Absorption (WADM)Maximum surge energy handling capabilityMeasured in joules (J), critical for industrial applications
Leakage CurrentOff-state current at rated voltageImpacts 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

ManufacturerRepresentative ProductKey Specifications
LittelfuseSM712-0212A, 13.3V clamping, bidirectional TVS for RS-485
BournsV14450A14mm MOV, 450VAC, 210J energy rating
STMicroelectronicsTV05C0600.5W, 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
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