When a p-n junction is switched from the forward to the reverse direction by a current ramp, the reverse recovery time t
rris found 1) either to be equal to the base lifetime τ if the ramp rate

, 2) to be equal to 0.79τ if

, or 3) to be equal to 0.7 τ if

. These results afford correlations between τ
rrand τ and also provide the basis for a useful method for measuring τ.