A GOA circuit based on LTPS semiconductor thin film transistor, comprising GOA units of a plurality of stages which are cascade coupled, and the GOA unit of each stage comprises:
- a scan control unit, a forward scan pull-down unit, a backward scan pull-down unit and an output unit;
- n is set to be a positive integer and except the GOA units of the first, the second, the next to last and the last stages, in the nth stage GOA unit:
- the scan control unit comprises:
- a first thin film transistor, and a gate of the first thin film transistor is electrically coupled to an output end of a two former stage n−2th GOA unit, and a source is electrically coupled to a forward scan direct current control signal, and a drain is electrically coupled to a source of a fourth thin film transistor;
- and a third thin film transistor, and a gate of the third thin film transistor is electrically coupled to an output end of a two latter stage n+2th GOA unit, and a drain is electrically coupled to the source of the fourth thin film transistor, and a source is electrically coupled to a backward scan direct current control signal;
- and the fourth thin film transistor, a gate of the fourth thin film transistor is electrically coupled to a constant high voltage level, and a drain is electrically coupled to a first node;
- the forward scan pull-down unit comprises:
- a fifth thin film transistor, and a gate of the fifth thin film transistor is electrically coupled to the forward scan direct current control signal, and a source is electrically coupled to the constant high voltage level, and a drain is electrically coupled to a second node;
- a sixth thin film transistor, and a gate of the sixth thin film transistor is electrically coupled to the backward scan direct current control signal, and a drain is electrically coupled to the second node, and a source is electrically coupled to the constant low voltage level;
- a thirteenth thin film transistor, and a gate of the thirteenth thin film transistor is electrically coupled to the first node, and a drain is electrically coupled to the second node, and a source is electrically coupled to the constant low voltage level;
- a ninth thin film transistor, and a gate of the ninth thin film transistor is electrically coupled to the second node, and a source is electrically coupled to the constant low voltage level, and a drain is electrically coupled to the first node;
- and a tenth thin film transistor, a gate of the tenth thin film transistor is electrically coupled to the second node, and a source is electrically coupled to the constant low voltage level, and a drain is electrically coupled to and output end;
- the backward scan pull-down unit comprises:
- an eighth thin film transistor, and a gate of the eighth thin film transistor is electrically coupled to the forward scan direct current control signal, and a source is electrically coupled to the constant low voltage level, and a drain is electrically coupled to a third node;
- a seventh thin film transistor, and a gate of the seventh thin film transistor is electrically coupled to the backward scan direct current control signal, and a source is electrically coupled to the constant high voltage level, and a drain is electrically coupled to the third node;
- a fourteenth thin film transistor, and a gate of the fourteenth thin film transistor is electrically coupled to the first node, and a drain is electrically coupled to the third node, and a source is electrically coupled to the constant low voltage level;
- an eleventh thin film transistor, a gate of the eleventh thin film transistor is electrically coupled to the third node, and a source is electrically coupled to the constant low voltage level, and a drain is electrically coupled to the first node;
- and a twelfth thin film transistor, and a gate of the twelfth thin film transistor is electrically coupled to the third node, and a source is electrically coupled to the constant low voltage level, and a drain is electrically coupled to the output end;
- the output unit comprises:
- a second thin film transistor, and a gate of the second thin film transistor is electrically coupled to the first node, and a source is electrically coupled to a Mth clock signal, and a drain is electrically coupled to an output end;
- and a bootstrap capacitor, and one end of the bootstrap capacitor is electrically coupled to a first node, and the other end is electrically coupled to the output end;
- voltage levels of the forward scan direct current control signal and the backward scan direct current control signal are opposite.