Patent ID: 7521999
Filing Date: 2009-04-21
Classification: H01L,H03F

Abstract:
1. A differential amplifier, comprising: first and second transistors each having a first gate, a second gate, a source, and a drain open to a drain side, the first gate and the second gate being controlled independently, a differential input being supplied to between the first gate of the first transistor and the first gate of the second transistor, and the source of the first transistor and the source of the second transistor being connected in common to a first reference potential; first and second load circuits each connected to each of the drain side of the first transistor and the drain side of the second transistor; a detection circuit configured to detect a common-mode voltage between the drain side of the first transistor and the drain side of the second transistor; a comparison and amplification circuit configured to amplify the common-mode voltage in comparison with a second reference potential and to supply an output signal thereof to both of the second gate of the first transistor and the second gate of the second transistor; third and fourth transistors each inserted and connected between the drain of each of the first and second transistors and each of the first and second load circuits, so that sources thereof are on a side of the first or second transistor and drains thereof are on a side of the first or second load circuits; and fifth and sixth transistors each inserted and connected between each of the drains of the third and fourth transistors and each of the first and second load circuits, so that sources thereof are on a side of the first or second load circuit and drains thereof are on a side of the third or fourth transistor.