A logarithmic unit of ratio equal to a factor of 10. In electronics, it is heavily used to describe frequency ranges on a Bode plot, filter roll-off rates, and the scaling of passive components. A set of resistors that jump from 10 ohms to 100 ohms to 1 kilo-ohm are separated by decades.
Heard on the job
The low-pass filter has a roll-off of 40 dB per decade once you pass the cutoff frequency.
Related terms
Decade box
A piece of bench equipment containing highly precise, switch-selectable passive components arranged in factors of ten.
Roll off
To gradually attenuate a signal's amplitude as its frequency moves past a specific cutoff point.
Frequency domain
A method of analyzing a signal by looking at its frequency components rather than its changes over time.