The standard circuit for the LM3404 board has also been optimized to run from 24V to support outdoor and general purpose illumination requirements. A second circuit using the LM3404HV runs from 48V. The DIM pin of the LM3404 is a fast enable pin, meaning that when it is at logic low and the LED output current is off, the remaining circuits stay active. This allows the LM3404 to respond very quickly when the DIM pin signal changes to logic high. The result is that delay time tD is minimized.