Clock rate

The switching frequency ( SI unit: Hz) indicates the number of switching on and off an electronic component or a circuit per second.

In this case, Toff is the time in the off state, Tanstieg the rise time, the time Ton in the on state and the fall time Tabfall. Rise and fall times are typically significantly smaller than the switching state and time can be neglected if necessary, so that the equation becomes

Can be simplified.

The higher the switching frequency, the more frequently can be performed, the switching operation per second, and the faster the switching operation.

In switching power supplies, the switching frequency is often in the range of 10 kHz to 20 kHz, which is the most part in the audible range of the human ear and perceived as a whistling sound monotonous.

Transistors of high switching frequencies, for example, enable the clock frequencies of modern processors, and satellite communication in the GHz range.

The switching frequency is not to be confused with the indication of the maximum switching cycles. This indicates the average number of switching operations can be carried out, until the wear on the contacts, the extent is advanced, that a reliable connection or disconnection can not be ensured. This indication occurs exclusively for mechanical contacts like relays and reed contacts. In semiconductors, the number of switching cycles is unlimited.