noun, noun which may take the genitive case particle 'no'
falling edge; trailing edge; decay
Technical term used in electronics and signal processing for the falling or trailing part of a waveform, pulse, or signal. Often contrasted with 立ち上がり (rising edge).
この回路は信号の立ち下がりを検出します。
This circuit detects the falling edge of the signal.
立ち下がり時間が短いほど高速動作に適している。
The shorter the fall time, the more suitable it is for high-speed operation.
optical fall time
Compound of 立ち (continuative form of 立つ, 'to stand') + 下がり (continuative form of 下がる, 'to fall'). Literally 'standing-falling', used as a technical term for the falling edge of a signal.