Patent ID: 11971734

Abstract:
Disclosed is a low dropout linear voltage regulator and a control circuit thereof. The control circuit comprises an error amplifier, a foldback current-limiting protection circuit, an undershoot suppression circuit and an output detection circuit. The foldback current-limiting protection circuit limits the output current of power transistor and performs short circuit protection, the undershoot suppression circuit pulls the control terminal of the power transistor to low voltage level when the output voltage undershoots. The output detection circuit judges whether the output voltage rises to a preset voltage value in the startup stage, and before the output voltage rises to the preset voltage value, disables the undershoot suppression circuit and the foldback characteristic of the foldback current-limiting protection circuit, which can prevent normal startup of the circuit from being affected by a maloperation of the foldback current-limiting protection circuit and the undershoot suppression circuit during the startup process, improve on-load startup ability.