초록 ▼

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 vo

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. Furthermore, 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.

대표청구항 ▼

An operational amplifier circuit, comprising: a first input transistor and a second input transistor having respective first and second conductive paths and gate terminals, said gate terminals are connected to respective first and second input conductors; a first summing node coupled to receive mirr

An operational amplifier circuit, comprising: a first input transistor and a second input transistor having respective first and second conductive paths and gate terminals, said gate terminals are connected to respective first and second input conductors; a first summing node coupled to receive mirrored current from said first conductive path as well as current produced through a third conductive path formed by a signal upon the gate terminal of said second input transistor; and an output circuit coupled between said first summing node and an output conductor, wherein said output circuit is configured to convert current within said first summing node to an output voltage forwarded to said output conductor, said output circuit comprising a pullup transistor connected to convey a high output voltage upon said output conductor and a pulldown transistor connected to convey a low output voltage upon said output conductor, whereupon said pullup transistor is deactivated and said pulldown transistor is activated in response to a summed current received at said first summing node, whereby said output conductor is discharged to a ground voltage supplied to said operational amplifier circuit during use.