# Varistors, MOVs **URL:** \ **Category:** Product Selection Guide\ **Tags:** circuit-protection, power, transient-voltage-suppressors-tvs\ **Created:** [July 3, 2023, 10:28pm UTC](https://forum.digikey.com/t/varistors-movs/32528 "2023-07-03T22:28:28Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![raelynn.roen](https://sea2.discourse-cdn.com/digikey/user_avatar/forum.digikey.com/raelynn.roen/32/46693_2.png) [@raelynn.roen](https://forum.digikey.com/u/raelynn.roen)\ **Post date:** [July 3, 2023, 10:28pm UTC](https://forum.digikey.com/t/varistors-movs/32528/1 "2023-07-03T22:28:28Z")
This Product Selection Guide contains information to help select products in the [Varistors, MOVs](https://www.digikey.com/en/products/filter/transient-voltage-suppressors-tvs/varistors-movs/141) category on [DigiKey.com](http://DigiKey.com) > Transient voltage suppression (TVS) products based on Metal Oxide Varistor (MOV) technology are used to protect electrical and electronic devices against excess voltage hazards, such as may be caused by lighting induced transients, static electricity, or similar hazards. Their relatively high parasitic capacitance limits their application to low frequency circuits such as AC utility power inputs, in which application they excel due to their comparably high power dissipation capability and clamping behavior, which allows continued operation of protected devices without need of a reset process following a protection event, as is common with crowbar protection mechanisms. **Selection**** Characteristics** > **Maximum AC Volts:** The maximum RMS (sine wave) AC voltage that can be applied to the part continuously without resulting damage; the maximum AC working voltage of the part. > **Maximum DC Volts:** The maximum DC voltage that can be applied to the part continuously without resulting damage; the maximum DC working voltage of the part. > **Varistor Voltage (Min):** The minimum voltage required to force a test current of manufacturer-defined amplitude through an over-voltage protection device. > **Varistor Voltage (Typ):** The typical voltage required to force a test current of manufacturer-defined amplitude through an over-voltage protection device. > **Varistor Voltage (Max):** The maximum voltage required to force a test current of manufacturer-defined magnitude through an over-voltage protection device. > **Current - Surge:** Maximum allowed transient peak current, usually based on an IEC61000-4-5 standard 8/20us waveform. > **Energy:** The maximum amount of energy a device is rated to absorb during a single, non-repetitive protection event. Values refer to measurements made using a standardized test waveform. > **Number of Circuits:** The number of individual channels the device can provide independent protection to. > **Capacitance @ Frequency:** Characterizes the amount of capacitive loading a device presents to a circuit that it is used to protect. > **Operating Temperature:** Recommended operating temperature, typically given in a range or as a maximum. Exceeding these temperatures may affect performance or damage the device and other system components. > **Features:** These are different capabilities or properties of the device such as high surge and thermally protected. > **Mounting Type:** Indicates how the device is attached. > **Package / Case:** Indicates the type of protective case used on an electronic component to allow easy handling, installation, and protection. This selection was determined to be the closest industry standard applicable to the suppliers device packaging. Typically it is best to check the actual dimensions from the datasheet rather than depend on this terminology when designing your circuit. **Product**** Examples** [![Image](https://global.discourse-cdn.com/digikey/original/3X/c/0/c080b66e2ddef4956d20a206bc628b873b7bb3ab.png)](https://www.digikey.com/en/products/detail/bourns-inc/CG0603MLA-18KE/2538081) | MFR PART # | CG0603MLA-18KE | | --- | --- | | DIGIKEY PART # | [CG0603MLA-18KETR-ND - Tape & Reel (TR)](https://www.digikey.com/en/products/detail/bourns-inc/CG0603MLA-18KE/2538081) | | MANUFACTURER | Bourns Inc. | | DESCRIPTION | 28 V 30 A Varistor 1 Circuit Surface Mount, MLCV 0603 (1608 Metric) | | DATASHEET | [Click Here](https://www.bourns.com/docs/Product-Datasheets/MLA.pdf) | [![Image](https://global.discourse-cdn.com/digikey/original/3X/c/2/c278706afac7780941ad164d5cbcc38076c0913b.jpeg)](https://www.digikey.com/en/products/detail/epcos-tdk-electronics/B72220S0301K551/3500975) | MFR PART # | B72220S0301K551 | | --- | --- | | DIGIKEY PART # | [495-6539-2-ND - Tape & Reel (TR)](https://www.digikey.com/en/products/detail/epcos-tdk-electronics/B72220S0301K551/3500975) | | MANUFACTURER | EPCOS - TDK Electronics | | DESCRIPTION | 470 V 8 kA Varistor 1 Circuit Through Hole Disc 20mm | | DATASHEET | [Click Here](https://www.tdk-electronics.tdk.com/inf/70/db/var/SIOV_Leaded_StandarD.pdf?ref_disty=digikey) | [![Image](https://global.discourse-cdn.com/digikey/original/3X/7/a/7a65b4762609ddfd0ae6976cabf4b00549ecec4b.jpeg)](https://www.digikey.com/en/products/detail/littelfuse-inc/V271BA60/485726) | MFR PART # | V271BA60 | | --- | --- | | DIGIKEY PART # | [F4092-ND](https://www.digikey.com/en/products/detail/littelfuse-inc/V271BA60/485726) | | MANUFACTURER | Littelfuse Inc. | | DESCRIPTION | 430 V 50 kA Varistor 1 Circuit Chassis Mount Encased Disc | | DATASHEET | [Click Here](https://www.littelfuse.com/~/media/electronics/datasheets/varistors/littelfuse_varistor_ba_bb_datasheet.pdf.pdf) | [![Image](https://global.discourse-cdn.com/digikey/original/3X/c/c/ccd1f809d4db985529d4a639aee65f9da0b20c74.jpeg)](https://www.digikey.com/en/products/detail/littelfuse-inc/V321HF34/1210850) | MFR PART # | V321HF34 | | --- | --- | | DIGIKEY PART # | [V321HF34-ND](https://www.digikey.com/en/products/detail/littelfuse-inc/V321HF34/1210850) | | MANUFACTURER | Littelfuse Inc. | | DESCRIPTION | 510 V 40 kA Varistor 1 Circuit Bolt Mount Square 34mm, Tabs | | DATASHEET | [Click Here](https://www.digikey.com/en/htmldatasheets/production/42523/0/0/1/hb34-hf34-hg34-series) | **Schematic**** Symbol** ![image](https://global.discourse-cdn.com/digikey/original/3X/4/c/4c0a1e4b14c46b295276e1d217ab3ff5dcedabe9.png) ###### Schematic symbol courtesy of [Scheme-it](https://www.digikey.com/en/schemeit/). Please see their website for more information and symbols. **Media**** Links** Videos [Varistors - Ideal Protection Devices (full version)](https://www.digikey.com/en/videos/e/epcos/varistors--ideal-protection-devices--full-version) [HMOV Series - High Operating Temperature Varistors](https://www.digikey.com/en/videos/l/littelfuse/hmov-series---high-operating-temperature-varistors) [MLVC Multilayer Chip Varistors from Eaton](https://www.digikey.com/en/videos/e/eaton-electronics-division/mlvc-multilayer-chip-varistors-from-eaton) Product Training Modules [Metal Oxide Varistors - Littelfuse](https://www.digikey.com/en/ptm/l/littelfuse-inc/metal-oxide-varistors) [Advantages of Using a Varistor - KEMET](https://www.digikey.com/en/ptm/k/kemet/advantages-of-using-a-varistor) [VDRUS Series Varistors - Vishay/BC Components](https://www.digikey.com/en/ptm/v/vishay-bc-components/ultra-surge-metal-oxide-vdrus-series-varistors) [Thermal Fuse Varistors - Epcos](https://www.digikey.com/en/ptm/e/epcos-inc/thermal-fuse-varistors) [Suppressors - Multi-Layer Varistors - Panasonic](https://www.digikey.com/en/ptm/p/panasonic-electronic-components/esd-solutions--esd-suppressors-and-multi-layer-varistors) [VCAS Auto Series - KYOCERA AVX](https://www.digikey.com/en/ptm/a/avx-corporation/vcas-series-auto-multi-layer-varistor) Blogs [Protect your Product from ESD](https://www.digikey.com/en/maker/blogs/protect-your-product-from-esd) TechForum [Varistor Specifications: TVS - Varistors, MOVs](https://forum.digikey.com/t/varistor-specifications-tvs-varistors-movs/969) [What Is the Failure Mode of a Varistor?](https://forum.digikey.com/t/what-is-the-failure-mode-of-a-varistor/4280) ### If you have any general questions on the specifications for selecting [Varistors, MOVs](https://www.digikey.com/en/products/filter/transient-voltage-suppressors-tvs/varistors-movs/141), please reply using the button below. If you have questions on specific Varistors, MOVs please post those questions in the [Circuit Protection](https://forum.digikey.com/c/power/circuit-protection/111) category.