CURRENT SOURCE START CIRCUIT

摘要

PURPOSE:To solve a problem that time is required before a current source circuit operates stably and the above time is different also according to the size of a transistor and the arrangement of the transistor and wiring, etc., at the surroundings. CONSTITUTION:When the sleep signal SP of an L level is inputted to an input terminal 1 in order to make a current source operate, a PMOS 3 is turned off, and the drain potential of the PMOS 4 is separated from supply potential VDD. When the sleep signal SP of the L level is inputted to a delay circuit 10a, the signal VA of the L level is outputted from the delay circuit 10a after being delayed by prescribed time. NMOSs 10b and 10c are turned on for this delay time, and a current ID flows from the drain electrode of the PMOS 4 to GND through the NMOSs 10b and 10c, and the potential of the drain electrode of the PMOS 4 falls, and the PMOSs 4 and 5 are turned on, and the current flows, and the current source circuit operates stably.