Low dropout regulator

A low dropout regulator is applied to a power supply system and comprises a voltage source, a ground end, an error amplifying circuit (320), a control circuit (350), a power tube circuit (330) and an output node. The power tube circuit (330) comprises a first power tube (331) and a second power tube (332) which are connected in series between a voltage source and a ground end, and a common connection point of the first power tube (331) and the second power tube (332) is coupled to an output node. The error amplification circuit (320) is used for providing a control voltage to the grid electrodes of the first power tube (331) and the second power tube (332) based on the voltage of the output node. The error amplifying circuit (320) comprises a first output end and a second output end, the first output end is coupled to a grid electrode of the first power tube (331), and the second output end is coupled to a grid electrode of the second power tube (332). The control circuit (350) comprises a third power tube (3