Some applications requires high performances power supply characteristics in terms of fast recover to properly work. In particular it happen in the sequential system, where if an unexpected and high current absorption happens the output voltage go dowun due to the slow power supply response. If in the system there are microprocessor or counters, functionality problems could happen. Some companies suggest integrated solutions, but the performances are not optimum due to recovery times around 40ms,with output current medium or low and high dropout voltage ( as it is shown in figure 1, LT1585 performances).