Output amplifier of a source driver and control method thereof

An output amplifier of a source driver, the output amplifier comprising:

• a first switch circuit configured to receive a positive reference signal and a negative reference signal of the source driver, wherein the first switch circuit has a first output terminal and a second output terminal configured to selectively output the positive reference signal and the negative reference signal;
• a first input stage circuit electrically connected to the first output terminal of the first switch circuit to receive one of the positive reference signal and the negative reference signal and to output a first received reference signal accordingly;
• a second input stage circuit electrically connected to the second output terminal of the first switch circuit to receive the other one of the positive reference signal and the negative reference signal and to output a second received reference signal accordingly;
• a first active load circuit configured to receive one of the first received reference signal and the second received reference signal;
• a second active load circuit configured to receive the other one of the first received reference signal and the second received reference signal;
• a third switch circuit electrically connected to the first active load circuit, wherein the third switch circuit has a first output terminal and a second output terminal, and the third switch circuit is configured to select one of the first output terminal and the second output terminal to output one of the first received reference signal and the second received reference signal;
• a fourth switch circuit electrically connected to the second active load circuit, wherein the fourth switch circuit has a first output terminal and a second output terminal, and the fourth switch circuit is configured to select one of the first output terminal and the second output terminal to output the other one of the first received reference signal and the second received reference signal;
• a first positive output stage circuit electrically connected to the first output terminal of the third switch circuit;
• a second positive output stage circuit electrically connected to the second output terminal of the third switch circuit;
• a first negative output stage circuit electrically connected to the first output terminal of the fourth switch circuit;
• and
• a second negative output stage circuit electrically connected to the second output terminal of the fourth switch circuit;
• wherein an output terminal of the first positive output stage circuit and an output terminal of the first negative output stage circuit are electrically connected together, and an output terminal of the second positive output stage circuit and an output terminal of the second negative output stage circuit are electrically connected together, and a power voltage source and a half-power voltage source are electrically connected to the first positive output stage and the second output stage to provide a power voltage and a ground reference voltage of the first positive output stage and the second positive output stage, and a ground voltage source and the half-power voltage source are electrically connected to the first negative output stage and the negative output stage to provide a ground reference voltage and a power voltage of the first negative output stage and the second negative output stage, and a value of the voltage of the half-power voltage source is between a value of the voltage of the power voltage source and a value of the voltage of the ground voltage source.

A control method of an output amplifier of a source driver, comprising:

• providing a first switch circuit, a second switch circuit, a third switch circuit, a first input stage circuit, a second input stage circuit, a first active load circuit, a second active load circuit, a first positive output stage circuit, a first negative output stage circuit, a second positive output stage circuit and a second negative output stage circuit, wherein the first switch circuit receives a positive reference signal and a negative reference signal of the source driver;
• performing a first display stage comprising:
• setting the first switch circuit to output the positive reference signal through a first output terminal and to output the negative reference signal through a second output terminal;
• receiving the positive reference signal and the negative reference signal respectively to obtain a first received reference signal and a second received reference signal by using the first input stage circuit and the second input stage circuit;
• receiving the first received reference signal and the second received reference signal respectively by using the first active load circuit and the second active load circuit;
• and
• setting the second switch circuit and the third switch circuit to respectively receive the first received reference signal and the second received reference signal and to selectively output the received reference signal and the second received reference signal to the first positive output stage circuit, the first negative output stage circuit, the second positive output stage circuit and the second negative output stage circuit;
• and
• performing a second display stage wherein the second display stage comprises:
• switching the first switch circuit to output the positive reference signal through the second output terminal and to output the negative reference signal through the first output terminal;
• receiving the positive reference signal and the negative reference signal respectively to obtain a first received reference signal and a second received reference signal by using the first input stage circuit and the second input stage circuit;
• receiving the first received reference signal and the second received reference signal respectively by using the first active load circuit and the second active load circuit;
• and
• switching the second switch circuit and the third switch circuit to respectively receive the first received reference signal and the second received reference signal and to selectively output the received reference signal and the second received reference signal to the first positive output stage circuit, the first negative output stage circuit, the second positive output stage circuit and the second negative output stage circuit.