Operational amplifier based on metal-oxide TFT, chip, and method

An operational amplifier based on a metal-oxide thin-film transistor (TFT), comprising:

• an auxiliary amplifier comprising two first circuits in mutual symmetry, wherein each of the two first circuits is configured to adopt a two-stage positive feedback structure and comprises a fifth transistor, a seventh transistor, an eleventh transistor, a first amplifying unit, and a second amplifying unit, with a gate of the fifth transistor serving as an input end of the operational amplifier, a drain of the fifth transistor being connected to a source of the seventh transistor, a drain of the eleventh transistor, an input end of the first amplifying unit and an input end of the second amplifying unit, an output end of the first amplifying unit being connected to a gate of the seventh transistor, and an output end of the second amplifying unit being connected to a gate of the eleventh transistor;
• a bootstrap gain-increasing amplifier comprising two second circuits in mutual symmetry, wherein each of the two second circuits comprises a first transistor, a second transistor, and a current source unit with a bootstrap structure, a gate of the second transistor being connected to the drain of the fifth transistor, a drain of the second transistor being connected to the current source unit, a source of the second transistor being connected to a drain of the first transistor and the gate of the fifth transistor, a source of the first transistor being grounded, and the drain of the second transistor serving as an output end of the operational amplifier.