DRIVER CIRCUIT OF EL DISPLAY PANEL

摘要

A source driver circuit of EL display panel in which variation of output current is suppressed. The source driver circuit comprises unit transistors (634) each representing one unit. The O-th bit comprises one unit transistor (634), the first bit comprises two unit transistors (634), the second bit comprises four unit transistors (634), the third bit comprises eight unit transistors (634), the fourth bit comprises sixteen unit transistors (634), and the fifth bit comprises thirty two unit transistors (634). Each unit transistor (634) constitutes a current mirror circuit in conjunction with a transistor (633a). The current flowing through the unit transistor (634) can be altered by regulating a current Ib flowing through the transistor (633a). When an output current circuit is constituted of unit transistors and the reference current is regulated, output current of the unit transistor can be regulated resulting in a highly accurate source driver IC in which variation of output current is suppressed.