The invention discloses an
overcurrent protection circuit for a low dropout linear
voltage regulator. The
overcurrent protection circuit for the low dropout linear
voltage regulator comprises a current sampling circuit, a current comparison circuit and an upward pull circuit, wherein the current sampling circuit samples gate-drain
voltage of a power tube of the low dropout linear
voltage regulator, and outputs a sampling current to the current comparison circuit, the current comparison circuit mirrors the sampling current through a
current mirror, and then compares the sampling current with a current of a
current source, and after output current value of the low dropout linear
voltage regulator exceeds current protection threshold value, control voltage output by the current comparison circuit powers on the upward pull circuit, and the upward pull circuit pulls up gate end voltage of the power tube of the low dropout linear
voltage regulator, and thereby limits increasing of the output current, and plays a part in
overcurrent protection. The overcurrent protection circuit for the low dropout linear voltage
regulator can effectively restrain
channel length modulation effects of a current sampling tube in the current sampling circuit, decreases occurrence rate of the problem that deviation between value of the current sampled by the current sampling circuit and ideal value is overlarge, improves current sampling accuracy of the overcurrent protection circuit, and obtains accurate starting threshold value of the overcurrent protection circuit.