TVS - varistors, MOV's

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.