Patent ID: 7170351

Claim:
A drive circuit comprising: a plurality of differential AB class amplifier circuits connected in parallel, wherein each of the plurality of differential AB class amplifier circuits is configured as a voltage follower to input one of a plurality of analog signals and drive one of a plurality of data lines based on said one of a plurality of analog signals; and a common bias circuit which generates a first bias signal set and a second bias signal set, said first bias signal set comprising a first bias signal and a second bias signal, wherein said common bias circuit sets said first and second bias signals to one of a ground voltage level and a power supply voltage level in a test mode; wherein each of said plurality of differential AB class amplifier circuits comprises: an N-channel differential amplifier circuit connected between a power supply terminal and a ground terminal, said N-channel differential amplifier circuit being capable of inputting a differential signal and outputting a first output signal onto a first output line based on said first bias signal set, wherein said N-channel differential amplifier circuit contains an N-channel current source MOS transistor controlled based on said first bias signal of said first bias signal set; a P-channel differential amplifier circuit connected between said power supply terminal and said ground terminal in parallel to said N-channel differential amplifier circuit to operate independently from said N-channel differential amplifier circuit, said P-channel differential amplifier circuit being capable of inputting said differential signal and outputting a second output signal onto a second output line based on said first bias signal set, wherein said P-channel differential amplifier circuit contains a P-channel current source MOS transistor controlled based on said second bias signal of said first bias signal set; and an output stage circuit capable of generating a drive signal from said first and second output signals based on said second bias signal set and outputting said drive signal onto an output terminal.