| 摘要 |
A rail-to-rail operational amplifier and a display driver IC are provided to obtain little power consumption and high slew rate by varying first input stage current and second input stage current proportionally to voltage difference of a differential input signal pair. According to voltage difference of a differential input signal pair, a first input stage circuit(100) provides first input stage current. According to the voltage difference of the differential input signal pair, a second input stage circuit(200) provides second input stage current. An output stage circuit(320) produces output signal based on the first and second input stage currents. The first input stage circuit and the second input stage circuit have similar configuration. The first input stage circuit has a differential amplifier, a first adaptive biasing circuit and a second adaptive biasing circuit. According to the differential amplifier(110) is the voltage difference of the differential input signal pair, it is generated the first current and the complementarily controlled second current. The first adaptive biasing circuit(120) controls first adaptive variable current for comprising tail current of the differential amplifier based on the first current. The second adaptive biasing circuit(130) controls the second adaptive variable current for comprising the tail current of the differential amplifier based on the second current. The first adaptive variable current and the second adaptive variable current are complementarily varied based on the voltage difference of the differential input signal pair. |
