TVS - Varistors, MOVs

Image Part Number Description / PDF Quantity Rfq
VCUG120075H1TP

VCUG120075H1TP

Elco (AVX)

TRANSGUARD

0

VCAS120660M131RP

VCAS120660M131RP

Elco (AVX)

TRANSGUARD

0

VCUG120100L1TP

VCUG120100L1TP

Elco (AVX)

TRANSGUARD

0

VCUG040050L1WP

VCUG040050L1WP

Elco (AVX)

TRANSGUARD

0

VCAS120642L800DP

VCAS120642L800DP

Elco (AVX)

TRANSGUARD

0

VCAS080518C400TP

VCAS080518C400TP

Elco (AVX)

TRANSGUARD

0

VCAS080526A580DP

VCAS080526A580DP

Elco (AVX)

TRANSGUARD

0

VC060318A400TP

VC060318A400TP

Elco (AVX)

TRANSGUARD

0

VCUG120050L1DP

VCUG120050L1DP

Elco (AVX)

TRANSGUARD

0

VCUG120030L1DP

VCUG120030L1DP

Elco (AVX)

TRANSGUARD

0

VCUG060030L1TP

VCUG060030L1TP

Elco (AVX)

TRANSGUARD

0

VA100026D580RL

VA100026D580RL

Elco (AVX)

VARISTOR LEADED

0

VC12LC18A500TP

VC12LC18A500TP

Elco (AVX)

TRANSGUARD

0

VCUG060030L1DP

VCUG060030L1DP

Elco (AVX)

TRANSGUARD

0

VC120626D580TP

VC120626D580TP

Elco (AVX)

TRANSGUARD

0

MG064S18A400TP

MG064S18A400TP

Elco (AVX)

MULTIGUARD

0

VCUG080030H1TP

VCUG080030H1TP

Elco (AVX)

TRANSGUARD

0

VC080514C300TP

VC080514C300TP

Elco (AVX)

TRANSGUARD

0

VCAS120642L800RP

VCAS120642L800RP

Elco (AVX)

TRANSGUARD

0

VCUG120050L1RP

VCUG120050L1RP

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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