Output stage circuit

An output stage circuit, comprising:

• a first transistor, comprising a first terminal coupled to a first power terminal for receiving a first voltage, a second terminal coupled to an output terminal of the output stage circuit, a third terminal coupled to an input terminal for receiving an input voltage, and a fourth terminal coupled to a second power terminal for receiving a second voltage;
• a second transistor, comprising a first terminal coupled to ground, a second terminal coupled to the output terminal, a third terminal coupled to the input terminal for receiving the input voltage, and a fourth terminal coupled to ground;
• and
• a current source, coupled to the output terminal for providing a constant current;
• wherein the first voltage equals half the second voltage.

An output stage circuit for an operational amplifier, comprising:

• a pulling-up device, comprising a first terminal coupled to a first node, a second terminal coupled to an output terminal of the output stage circuit, and a third terminal coupled to an input terminal for receiving an input voltage, wherein the pulling pulling-up device pulls up a voltage at the output terminal when the pulling-up device is conducted in response to the input voltage;
• a pulling-down device, comprising a first terminal coupled to a second node, a second terminal coupled to the output terminal, a third terminal coupled to the input terminal for receiving the input voltage, and a fourth terminal coupled to a reference voltage, wherein the pulling-down device pulls down the voltage at the output terminal when the pulling-down device is conducted in response to the input voltage;
• and
• a current source, coupled to the output terminal for providing a constant current;
• wherein a voltage of the second terminal node is between a voltage of the first terminal node and the reference voltage.

An output stage circuit for an operational amplifier, comprising:

• a pulling-up device, comprising a first terminal coupled to a first node, a second terminal coupled to an output terminal of the output stage circuit, a third terminal coupled to an input terminal for receiving an input voltage, and a fourth terminal coupled to a power terminal for receiving a power voltage, wherein the pulling pulling-up device pulls up a voltage at the output terminal when the pulling-up device is conducted in response to the input voltage;
• a pulling-down device, comprising a first terminal coupled to a second node, a second terminal coupled to the output terminal, and a third terminal coupled to the input terminal for receiving the input voltage, wherein the pulling-down device pulls down the voltage at the output terminal when the pulling-down device is conducted in response to the input voltage;
• and
• a current source, coupled to the output terminal for providing a constant current;
• wherein a voltage of the first node is between the power voltage and a voltage of the second node.

An output stage circuit, comprising:

• a first device, comprising a first terminal coupled to a first node, a second terminal coupled to an output terminal of the output stage circuit, and a third terminal coupled to an input terminal for receiving an input voltage;
• a second device, comprising a first terminal coupled to a second node, a second terminal coupled to the output terminal, a third terminal coupled to the input terminal for receiving the input voltage, and a fourth terminal coupled to a reference voltage;
• and
• a current source, coupled to the output terminal for providing a constant current;
• wherein a voltage of the second node is between a voltage of the first node and the reference voltage.

An output stage circuit, comprising:

• a first device, comprising a first terminal coupled to a first node, a second terminal coupled to an output terminal of the output stage circuit, a third terminal coupled to an input terminal for receiving an input voltage, and a fourth terminal coupled to a power terminal for receiving a power voltage;
• a second device, comprising a first terminal coupled to a second node, a second terminal coupled to the output terminal, and a third terminal coupled to the input terminal for receiving the input voltage;
• and
• a current source, coupled to the output terminal for providing a constant current;
• wherein a voltage of the first node is between the power voltage and a voltage of the second node.