US Patent 7414472 Differential amplifying circuit

Disclosed is a differential amplifying circuit including an amplifying circuit, wherein 1) a drain of a sixth transistor is connected to a drain of an eighth transistor, and a drain of a tenth transistor is connected to a drain of a fourth transistor, and 2) a ratio between a total of gate widths of the fourth (or eighth) and tenth (or sixth) transistors (converted per unit gate length, and gate widths that follow are the same)and a gate width of a fifth (or ninth) transistor is nearly proportional to a current ratio between a first (or third) and second (or fourth) current source circuits, the gate width of the fourth (or eighth) transistor being equal to or more than that of the tenth (or sixth) transistor.