A low-dropout regulator with smooth peak current control (SPCC) topology for over current protection

The proposed LDO regulator with a smooth peak current control (SPCC) circuit can be simultaneously controlled by an error amplifier to regulate the output voltage and the peak current controller to limit the current level. The SPCC circuit detects the information of load current and the dropout voltage to smoothly switch between the error amplifier and the peak current controller. The experimental results show that when the load current exceed the peak current level, the over current protection can make the pass device operate as a current source to prevent the over current damaging the chip. Moreover, the control mechanism can return back to error amplifier control when load current becomes smaller than the limiting current and the output voltage close to the rated value for avoiding the oscillator. The output voltage is stable and varies smaller than 15 mV when a 160 mA load current step or a 2 V supply voltage step is put on this LDO regulator.