Differential amplifier circuit, data line driver using the same, and liquid crystal display apparatus

A data line driver comprising:

• a D/A (digital-to-analog) converter configured to output a gray scale voltage corresponding to a display data;
• and
• a differential amplifier circuit comprising an output terminal connected with a data line of a liquid crystal display panel, and having a non-inversion input terminal connected with said gray scale voltage and an inversion input terminal connected with said output terminal,
• wherein said differential amplifier circuit comprises:
• an NMOS transistor pair connected with said non-inversion input terminal and said inversion input terminal;
• a PMOS transistor pair connected with said non-inversion input terminal and said inversion input terminal;
• and
• an output circuit section,
• wherein said PMOS transistor pair comprises first and second PMOS transistors,
• wherein said NMOS transistor pair comprises first and second non-doped type NMOS transistors as a depletion type of NMOS transistors in which a channel region is formed in a P-type substrate without a P well, and
• wherein said output circuit section comprises a first current mirror of a folded cascode type connected with said first and second non-doped type NMOS transistors, and output an output voltage to said output terminal in response to a current from said first current mirror.

A liquid crystal display apparatus comprising:

• a liquid crystal display panel;
• and
• a data line driver configured to drive a data line of said liquid crystal display panel,
• wherein said data line driver comprises:
• a D/A (digital-to-analog) converter configured to output a gray scale voltage corresponding to a display data;
• and
• a differential amplifier circuit comprising an output terminal connected with said data line of a liquid crystal display panel, and having a non-inversion input terminal connected with said gray scale voltage and an inversion input terminal connected with said output terminal,
• wherein said differential amplifier circuit comprises:
• an NMOS transistor pair connected with said non-inversion input terminal and said inversion input terminal;
• a PMOS transistor pair connected with said non-inversion input terminal and said inversion input terminal;
• and
• an output circuit section,
• wherein said PMOS transistor pair comprises first and second PMOS transistors,
• wherein said NMOS transistor pair comprises first and second non-doped type NMOS transistors as a depletion type of NMOS transistors in which a channel region is formed in a P-type substrate without a P well, and
• wherein said output circuit section comprises a first current mirror of a folded cascode type connected with said first and second non-doped type NMOS transistors, and outputs an output voltage to said output terminal in response to a current from said first current mirror.