Shown on this slide are some waveforms from the DER-260 design example. The blue trace on top is the 5 V output. The yellow trace in the middle is bypass pin voltage, which is between 5.65 V and 5.85 V in normal operation. The purple feedback pin voltage trace stays at a constant 1.7 V under normal conditions. Shown in green, the power-down signal is the voltage fed to the base of the transistor between the bypass and feedback pins. When activated, it pulls the feedback pin high for longer than 2.5 mS, initiating the off-mode. It can be seen that when the feedback pin is pulled high, both the output voltage and bypass pin voltage start to decline. The output voltage collapses completely; while the bypass pin settles to its off-mode-regulated 4 V. There is actually a very small delay between the feedback pin being pulled above 1.7 V and the output voltage decline, but it is not visible here due to the long time base being shown.