Patent ID: 8232842

Claim:
An output buffer, comprising: a differential amplifier receiving an input signal and a feedback signal from an output terminal of the output buffer and accordingly controlling a level of a first control signal and a second control signal; a first output stage biased between a high voltage and a low voltage, judging whether to provide a first current to the output terminal of the output buffer according to the level of the first control signal and the second control signal; a first control stage biased under the high voltage, outputting one of the first control signal and the high voltage according to the level of the first control signal; a second control stage biased under the low voltage, outputting one of the second control signal and the low voltage according to the level of the second control signal; and a second output stage biased between the high voltage and the low voltage, judging whether to provide a second current to the output terminal of the output buffer according to a signal generated by the first control stage and the second control stage.