Time constant
Also: τ, tau
A timescale describing how quickly a first-order system approaches a new value.
After one τ a first-order rise completes about 63.2% of its total change, or a decay retains about 36.8%.
- Units
- seconds (s)
- Formula
τ = RC for an RC circuit
Example 10 kΩ and 100 µF give τ = 1 s.
Common misconception The response is not completely finished after one time constant.