![circuit-protection hero picture panasonic industry](https://mediac.industry.panasonic.eu/p/styles/hero_style_fallback_500x960_/public/2021-12/circuit_protection_01-min.png?VersionId=ez1LMHwkM0shbR1k9v1xGgi.AicTG4bg&h=02930eed&itok=Dm0SFVB5)
Multilayer varistors
![circuit protection multilayer varistor hero](https://mediac.industry.panasonic.eu/p/styles/hero_secondary_image/public/2022-11/circuit-protection_multilayer_varistors_hero-min.png?VersionId=fL6.06fqVrJ218dXCjtRqCKsobDYBgsX&itok=Ra3KB8Ho)
About the multilayer chip varistor
![circuit-protection multilayer-varistors construction](https://mediac.industry.panasonic.eu/p/styles/500x/public/2022-11/circuit-protection_multilayer-varistors_construction_Body_picture-min.jpg?VersionId=uFwz_eurVlAO.WDvZBg2DY4PVXnq7s1V&itok=8wQsbocB)
Varistor stands for Variable Resistor.
It’s a voltage nonlinear resistor/voltage-dependent resistor which changes resistance value depending on applied voltage.
It is a ceramic electronic component and it's used to protect electronic equipment from the abnormal voltage, such as ESD (Electrostatic) and surge.
Characteristics:
- Achieve ESD protection excellent effect by own ceramics materials and process technology.
- It is possible to replace from the Zener diode, which contributes to reducing the size and weight of the equipment.
- The wide product line up of the laminate structure and applicable to wide range of applications from high-speed signal lines to the power supply.
Voltage vs. current
![circuit-protection multilayer-varistors Voltage-vs.-Current](https://mediac.industry.panasonic.eu/p/styles/500x/public/2021-02/circuit-protection_multilayer-varistors_Voltage-vs.-Current_Body_picture_0.jpg?VersionId=zPOlp291vnBCrOI3oNgxuQdQgblArkcs&itok=NhoaEON3)
Varistors' voltage/current characteristics are different from a normal fixed resister and resistance value is changed by applied voltage widely!
What is the function of multilayer varistor?
![circuit-protection multilayer-varistors Current-Voltage characteristics](https://mediac.industry.panasonic.eu/p/styles/500x/public/2021-02/circuit-protection_multilayer-varistors_Current-Voltage-characteristics_Body_picture.jpg?VersionId=6jZF6dhbnMuMzeLS8u6kGqXJVciN7ODG&itok=vshPm5YR)
Current-Voltage characteristics
Multilayer varistors protect electronic equipment from ESD (electrostatic discharge) by utilizing the characteristics of changing resistance values depending on applied voltage!
![circuit-protection multilayer-varistors ESD-suppression-mechanism](https://mediac.industry.panasonic.eu/p/styles/500x/public/2021-02/circuit-protection_multilayer-varistors_ESD-suppression-mechanism_Body_picture_0.jpg?VersionId=UPyKN.5BR3A7LEYlmu1mecQRX6l_7tUC&itok=A3cHFJ31)
ESD suppression mechanism
- Invading ESD into equipment.
- The resistance value of Varistor decreases rapidly by applied voltage exceeding varistor voltage.
- Varistor bypasses excessive current to a GND.
- Suppress ESD voltage and protect IC.
![circuit-protection multilayer-varistors ESD_suppression_effect](https://mediac.industry.panasonic.eu/p/styles/500x/public/2021-02/circuit-protection_multilayer-varistors_ESD_suppression_effect_Body_picture_0.jpg?VersionId=uMr3BenXudqfPf.u41XuNHU3q8s3O.bz&itok=BbgsC6Ur)
ESD suppression effect (example)
Multilayer varistors have excellent ESD suppression effect.
![circuit-protection multilayer varistors ESD suppression_effect graph](https://mediac.industry.panasonic.eu/p/styles/1200x500/public/2021-02/circuit-protection_multilayer-varistors_ESD_suppression_effect_graph_Body_picture_width_1200x500.jpg?VersionId=3_lQoCdQ79xZ3pGwPBFAQFqGqCIYIWie&h=f97871b5&itok=GmB1unX3)
Types and applications of ESD countermeasure components
Multilayer Varistor is mainly applied to general signal circuits and automotive ECU; it can be applied to various devices.
![circuit-protection multilayer-varistors Types applications_ESD](https://mediac.industry.panasonic.eu/p/styles/1200x500/public/2021-02/circuit-protection_multilayer-varistors_Types_applications_ESD_Body_picture_width_1200x500.jpg?VersionId=PLVN2GdNxbYRF8T58v_sChm1U8D83OqN&h=f97871b5&itok=1iqkR2Cl)
Application example: Smartphones
Multilayer varistor is used in small electronic devices, TVs and AV equipment, including smartphones as a countermeasure component for ESD from the human body.
![circuit-protection multilayer-varistors Smartphone](https://mediac.industry.panasonic.eu/p/styles/1200x500/public/2021-02/circuit-protection_multilayer-varistors_Smartphone_Body_picture_width_1200x500.jpg?VersionId=yvlcxMqfC1Kj1r_xK0LDyOlcJLVNHwSM&h=f97871b5&itok=5P2bKhPI)
Application example: Automotive equipment (ECU)
![circuit-protection multilayer-varistors Automotive-equipment](https://mediac.industry.panasonic.eu/p/styles/500x/public/2021-02/circuit-protection_multilayer-varistors_Automotive-equipment_Body_picture.jpg?VersionId=bEsZ_IaMODofCYVhniflGYeobt1LjCFw&itok=xqIhA4ii)
Multilayer Varistor is applied to general signal lines and power lines of automotive equipment.
- ECU for body
(Size 0402 / DC30V / V1mA 42V / 56pF max.) - LAN communication lines (CAN, LIN)
(Size 0402 / DC16V / V1mA 27V /20pF max.) - Car navigation system
(Size 0402 / DC16V / V1mA 27V / 20pF max.) - Back monitor camera
(Size 0603 / DC16V / V1mA 27V / 100pF max.) - Power seat
(Size 0603 / DC16V / V1mA 27V / 20pF max.) - Keyless entry device
(Size 0402 / DC11V / V1mA 18V / 150pF max.)