TVS - Varistors, MOVs

Image Part Number Description / PDF Quantity Rfq
9401100000

9401100000

Weidmuller

VARISTOR MODULE

0

9401210000

9401210000

Weidmuller

VARISTOR 22V 2KA MODULE

0

9401560000

9401560000

Weidmuller

VARISTOR 360V 4.5KA MODULE

0

9401500000

9401500000

Weidmuller

VARISTOR 120V 4.5KA MODULE

0

9401380000

9401380000

Weidmuller

VARISTOR 430V 8KA MODULE

0

9401660000

9401660000

Weidmuller

VARISTOR MODULE

0

9401650000

9401650000

Weidmuller

VARISTOR 47V 2KA MODULE

0

9401480000

9401480000

Weidmuller

VARISTOR MODULE

0

9401080000

9401080000

Weidmuller

VARISTOR MODULE

0

9401360000

9401360000

Weidmuller

VARISTOR MODULE

0

9401370000

9401370000

Weidmuller

VARISTOR MODULE

0

9401330000

9401330000

Weidmuller

VARISTOR MODULE

0

9401340000

9401340000

Weidmuller

VARISTOR 240V 6.5KA MODULE

0

9401530000

9401530000

Weidmuller

VARISTOR MODULE

0

9401670000

9401670000

Weidmuller

VARISTOR 68V 2KA MODULE

0

9401270000

9401270000

Weidmuller

VARISTOR MODULE

0

9401090000

9401090000

Weidmuller

VARISTOR MODULE

0

9401320000

9401320000

Weidmuller

VARISTOR MODULE

0

9401250000

9401250000

Weidmuller

VARISTOR 47V 2KA MODULE

0

9401740000

9401740000

Weidmuller

VARISTOR MODULE

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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