Patent ID: 7868695

Claim:
A differential amplifier comprising: a first differential amplifier circuit performing a differential amplification operation based on a difference between signals input from two input terminals; a second differential amplifier circuit performing a differential amplification operation based on a difference between signals input from the same two input terminals as the first differential amplifier circuit; a first source-grounded amplifier connected to an output of the first differential amplifier circuit; a second source-grounded amplifier connected to an output of the second differential amplifier circuit; a current mirror circuit connected to the second source-grounded amplifier and driven by a drain current of the second source-grounded amplifier; bias resistances connected to gates of the first source-grounded amplifier and the second source-grounded amplifier, respectively; and a bias circuit connected to the bias resistances; wherein gate biases of the first source-grounded amplifier and the second source-grounded amplifier are supplied from the bias circuit through the bias resistances; and wherein an output terminal is connected between one transistor of the current mirror circuit and the first source-grounded amplifier.