| 摘要 |
The op-amp circuit described herein utilizes current summing to substantially eliminate cross-over distortion. Therefore, the op-amp circuit is characterized by linearity over the operable voltage range of the amplifier. Additionally, the op-amp circuit is capable of rail-to-rail input and output voltage swings. Futhermore, the op-amp circuit is capable of operating with a power supply voltage as low as two volts when fabricated in modern CMOS fabrication processes, without requiring special processing steps. An output circuit within the op-amp circuit is configured with pullup and pulldown devices which combine to provide output voltages throughout the operable range of the op-amp. However, when an output voltage equal to the power supply voltage is desired, the pulldown device substantially stops its pulldown current flow. Therefore, the pullup device charges the output conductor of the op-amp circuit fully to the power supply voltage. Similarly, when an output voltage equal to the ground voltage is desired, the pullup device substantially stops its pullup current flow. Therefore, the pulldown device discharges the output conductor fully to the ground voltage.
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