CURRENT SOURCE, LIGHT-EMITTING ELEMENT DRIVE CIRCUIT AND DIGITAL/ANALOG CONVERTER

摘要

PROBLEM TO BE SOLVED: To provide a current source which is turned on/off at a high speed and can linearly change a current amount, and to provide a light-emitting element drive circuit and a digital-analog converter. SOLUTION: The digital analog converter is provided with a first MOS transistor M1, where the drain and the gate are set as current input ends; a first switch SW1 which is connected to a source of the first MOS transistor M1; a second MOS transistor M2 where a drain is set to be current output; a second switch SW2 connected to a source of the second MOS transistor M2; a third switch SW3, whose one end is connected to the drain and the gate of the first MOS transistor M1 and the other end is connected to a gate of the second MOS transistor M2, and a drive circuit "drive" for controlling the second switch SW2 and the third switch SW3. COPYRIGHT: (C)2005,JPO&NCIPI