This paper proposes an overcurrent protection circuit for low dropout regulators.The overcurrent protection circuit proposed in this paper is based on the SMIC 180 nm CMOS process and uses a 1.8 V power supply to improve the sampling accuracy of the output current,limit the maximum output current of the LDO power tube and reduce the current output of the power tube when the LDO output voltage is too low,without affecting the voltage drop of the original LDO power tube.After reaching the overcurrent limit,the load current and power consumption drop ratio is positively correlated,the higher the load current,the more the overall power consumption drops than the original.As the load current increases,the power consumption drop ratio gradually increases from 0％to 20％～30％before the current foldback is triggered;after the current foldback starts,the power consumption drop ratio gradually increases from 20％～30％to 99％.When the load current does not reach the current foldback threshold,the LDO transient performance is not affected;when the load current reaches the current foldback threshold,the output voltage drops by approximately 500 mV,but the rest of the transient performance is not affected.
维普
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