Patent ID: 6630863
Filing Date: 2003-10-07
Classification: H03F

Abstract:
A differential amplifier comprising:a first differential amplifier circuit which operates based on a first input voltage and includes a first transistor of a primary conductivity type and a second transistor of the primary conductivity type which makes up a differential pair with the first transistor of the primary conductivity type; a second differential amplifier circuit which operates based on a second input voltage and includes a first transistor of a secondary conductivity type and a second transistor of the secondary conductivity type which makes up a differential pair with the first transistor of the secondary conductivity type; a third transistor of the secondary conductivity type which operates based on a first signal from the first differential amplifier circuit; a third transistor of the primary conductivity type which is serially connected to the third transistor of the secondary conductivity type and operates based on a second signal from the second differential amplifier circuit; and a voltage control circuit which controls a voltage of a control terminal of the third transistor of the secondary conductivity type, based on a third signal from the second differential amplifier circuit, wherein a voltage between the third transistor of the secondary conductivity type and the third transistor of the primary conductivity type is used as an output voltage.