Modular power supply system including a power status signal generator to perform fast sag detection to input peak voltage

A modular power supply system, comprising:

• a power source;
• and
• a power status signal generator circuit connected to the power source for detecting a peak value of an input voltage received from the power source and generating a power status signal indicating a power supply status of the power source, wherein the power status signal generator circuit includes a peak detector that detects a voltage sag of the peak value of the input voltage received from the power source, and wherein the peak detector comprises a first voltage comparator that compares the input voltage received from the power source with a predetermined reference voltage and sends an output signal according to a comparison result thereof, a resistor-capacitor network connected to the first voltage comparator and is configured to charge and discharge the capacitor according to the output signal of the first voltage comparator, wherein a charging time of the capacitor is shorter than a discharging time thereof, and a second voltage comparator connected to the resistor-capacitor network that compares a terminal voltage of the capacitor of the resistor-capacitor network with the predetermined reference voltage and generates the power status signal according to a comparison result thereof.