Output amplifier and display driver

A display driver comprising a plurality of output amplifiers configured to amplify gradation voltages supplied thereto, so as to generate amplified gradation voltages, wherein

• said plurality of output amplifiers are constituted of a first output amplifier group and a second output amplifier group,
• each of said output amplifiers belonging to said first output amplifier group and said second output amplifier group includes:
• a differential unit configured to send a current corresponding to a voltage difference between said gradation voltage and said amplified gradation voltage to a first current line;
• a current mirror unit connected between a first voltage supply line to which a first voltage is supplied and a second voltage supply line to which a second voltage lower than said first voltage is supplied, the current mirror unit being configured to send a current to the second current line by an amount corresponding to an amount of the current flowing through said first current line;
• and
• an output unit including first and second drive lines respectively connected to said second current line, an output line through which said amplified gradation voltage is output, a first output transistor configured to send a current based on a voltage of said first drive line to said output line, and a second output transistor configured to send a current based on a voltage of said second drive line to said output line,
• said output unit of each of said output amplifiers belonging to said first output amplifier group includes a first voltage regulation circuit configured to control the voltage of said first drive line such that the voltage of said first drive line is higher than the voltage of said second drive line, and
• said output unit of each of said output amplifiers belonging to said second output amplifier group includes a second voltage regulation circuit configured to control the voltage of said second drive line such that the voltage of said second drive line is lower than the voltage of said first drive line.

An output amplifier configured to amplify a gradation voltage supplied thereto, so as to generate an amplified gradation voltage, the output amplifier comprising:

• a differential unit configured to send a current corresponding to a voltage difference between said gradation voltage and said amplified gradation voltage to a first current line;
• a current mirror unit connected between a first voltage supply line to which a first voltage is supplied and a second voltage supply line to which a second voltage lower than said first voltage is supplied, the current mirror unit being configured to send a current to the second current line by an amount corresponding to an amount of the current flowing through the first current line;
• and
• an output unit including first and second drive lines that are respectively connected to said second current line, an output line through which said amplified gradation voltage is output, a first output transistor configured to send a current based on a voltage of said first drive line to said output line, and a second output transistor configured to send a current based on a voltage of said second drive line to said output line, wherein
• said output unit includes a switch device configured to directly connect said second voltage supply line to said second drive line to apply the second voltage to said second drive line when the voltage of said second drive line is equal to or higher than the voltage of said first drive line.