a regulator and related method for providing a regulated voltage . the regulator includes a bipolar junction transistor as a charging circuit , a capacitive circuit formed for regulating the regulated voltage by bypass and regulation capacitors , an operational amplifier , a bandgap circuit , and a pre - charging circuit . the capacitive circuit receives current to establish the regulated voltage . according to the regulated voltage , the op - amp biases the base of the bjt to obtain the accurate regulated voltage to control a current conducted to the capacitive circuit by the bjt . when the regulator starts to work , the op - amp is disabled to prevent the bjt from providing current . instead the pre - charging circuit first provides a pre - charging current to charge the capacitive circuit , then the op - amp is enabled to turn on the bjt to charge the capacitive circuit and establish the steady - state regulated voltage .