Circuit Protection: Chip Varistors

Chip Varistors design engineers Panasonic
Multilayer Varistors EZJ-Z-P

Panasonic offers both single and multi-layer versions of Metal Oxide Varistors or Surge Absorbers.
Our MLCV's are available in several SMD Packages, various voltages and offer a wide range of peak current/energy handling.

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Related Information


Varistor stands for Variable Resistor. It’s a voltage nonlinear resistor/voltage-dependent resistor. It is an element that changes its resistance value depending on applied voltage. This is the ceramic electronic component the character of which is used to protect electronic devices from the abnormal voltage, such as lightning surge and static electricity.


Chip Varistor AppearanceChip Varistor Construction


Voltage vs. Current
Chip Varistor Voltage vs. Current
Varistor’s voltage/current characteristics differ from a fixed resister and the element changes its resistance values widely


Chip Varistor's Function

Current Voltage Characteristics
It protects electronic devices from electrostatic discharge (ESD) by utilizing its characteristic of changing resistance values depending on applied voltage
ESD Suppression Mechanism
ESD Suppression Effect
ESD suppression effect (ex.)


Our MLCV is top-level in the industry and possess following characteristics

The MLCV is small and surface-mount  type
     component and it is available in various
     sizes (0603・1005・1608).

  • It can contribute to miniaturization and lightening of various applications.

Our original ceramic material and process
     technology realized high reliability

  • Great ESD suppression effect
  • Having high ESD and surge tolerance

We prepared automotive lineups

  • Long-term life assurance (load life:2000h, temperature cycle: 2000c)
  • High heat resistance (up to 150℃)
  • In conformity to AEC-Q200 standard
  • ISO/TS16949 qualified



Chip Varistor is mainly applied to general signal circuits and in-vehicle devices. It can be applied to various devices.

Types and applications of electrostatic countermeasure components.

Examples of use

Chip Varistor Usage - Smartphone
Chip Varistor is used in small electronic devices,  TVs and AV devices, including smartphones as a countermeasure component for electrostatic discharge from a human body


Chip Varistor Usage - Automotive Device
Chip Varistor is applied and considered applying to automotive devices's general signal lines


Replacement of Zener Diodes (TVS Zener) with Multilayer Chip Varistors

 Zener Diodes (ZD)Multilayer Chip Varistor
StructureZener diodes(ZD)Multilayer chip varistor
V-I CurveZener diodes(ZD)V-I CurveMultilayer chip varistorV-I Curve
  • Widely applied as an electrostatic countermeasure (for automotive, ICT and so on)
  • 0402 (1006mm)size is the top-seller in the ICT field.
  • Unipolar (+/-), which means it is one-way ESD countermeasure, though, there is bidirectional products
  • Low-capacitance type is available
  • (less than or equal to 1pF)
  • Widely applied as an electrostatic countermeasure(for automotive, ICT and so on)
  • 0201 (0603mm) size is the top-seller in the ICT field.
  • Size and cost reduction is achievable
  • Having no polarity (+/-), which means it is a bidirectional ESD countermeasure
  • Low-capacitance type is not available (less than or equal to 1pF)


Benefit of Replacing ZD (TVS) with Multilayer Varistors

Downsizing / Weight savingHigh ESD / Surge capabilityLow cost
High reliability
Short lead time
Small and light weight ECU for energy saving and eco-carHigh surge current durability, e.g. Inductive loadNeeds of low-end customers for newly developing countries such as BRICsEnvironmental testing
(high temp, high humidity, heat cycle) and Long life (~2000h, ~2000c)
Flexibility for production volume fluctuation and Inventory reduction
Board space saving, weight reduction
Improve ESD/surge capability
Keep up better cost competitiveness
Beyond automotive requirement
Short lead time
Size and weight reduction of ECUBetter reliability of ECU!Low cost ECULong time reliability of ECUProduction efficiency of ECU


Recently, there are strong demands for smaller/low-cost electrostatic countermeasure components. The move to replace Zener diode with Varistor is accelerating.

Advantages of replacing Zener diode with Chip Varistor1
ESD Suppression Effect is Equal or Superior to ZD
IEC61000-4-2 (150pF, 330Ω/ contact discharge / 8kV)
Advantages of replacing Zener diode with Chip Varistor2
Reducing Mounting Area (Achieve Miniaturization and Space-Saving)
Advantages of replacing Zener diode with Chip Varistor3
Others … reducing components and costs, and shorten a delivery period etc.


Concrete Examples of Replacing Zener Diode with Chip Varistor
Advantages of replacing Zener diode with Chip Varistor4

Reliability Tests

We can conduct additional tests to meet your special demands.






Testing Methods

Performance, Evaluation items
1Vibration resistanceAcceleration: 5G
Vibrational frequency: 10~2000Hz
Sweep time: 20 minutes
12 cycles in 3 direction at right angles to each other
⊿V1mA : Within ±10%
2Shock resistanceAcceleration: 5G
Shock waveform: Semi sinusoidal wave, 11ms
Impact acceleration: 50G
Impact direction: X-X’ ,Y-Y’, Z-Z’(3 times for each direction)
⊿V1mA : Within ±10%
3Temperature cycleThe lowest temperature ±3℃(30±3 minutes)
→roomtemperature(less than or equal to 3 minutes)
→The highest temperature ±3℃(30±3 minutes)
→room temperature(less than or equal to 3 minutes)
This operation is one cycle. Repeat the cycle for 100 times
(automotive components: continue the cycle for 2000 times)
⊿V1mA : Within ±10%
⊿V1mA : Within ±10%
4Damp heat loadTesting temperature: 40±2℃(automotive 85±2℃)
Relative humidity: 90~95% (automotive 80~85%RH)
Applying voltage: maximum allowable voltage*
(specified respectively)
Testing time: 500+24/0 hours
(automotive: 2000+24/0 hours)
40℃/95%/DC Bias*/500h
⊿V1mA : Within ±10%
85℃/85%/DC Bias*/2000h
⊿V1mA : Within ±10%
5High temperature loadTesting temperature: 85±3℃(automotive: 125℃±3℃)
Applying voltage: maximum allowable voltage*
(specified respectively)
Testing time: 500+24/0 hours
(automotive: 2000+24/0 hours)
85℃/DC Bias*/500h
⊿V1mA : Within ±10%
150℃/DC Bias*/2000h
⊿V1mA : Within ±10%


Support Tools

We provide the device parameter, which is compatible with various simulator and CAD.

Chip Varistor Support Item


Get more information about the Device Parameter

Simulation Data Libraries
Frequency characteristic data, equivalent circuit models and S-parameter data can be downloaded for each individual item number.


In order to download the selected file, please check and accept our terms and conditions (*pdf file).

PIDEU_GT&Cs for Engineering Tools.pdf