Abstract: An active droop current sharing technique combined with current limiting function is employed in a parallel power supply. The parallel power supply is characterized with a current sensing amplifier that generates a current feedback signal representing a difference between a nominal output voltage and a fractional output voltage. The current sensing amplifier is coupled to a threshold level generator providing a threshold level defining a voltage level corresponding to a maximum allowed output current of the parallel power supply. If the voltage level of the current feedback signal exceeds the threshold level, the threshold level generator is turned on and the current feedback signal is coupled to a switching controller to adjust the output voltage of the power converter for properly addressing the current imbalance among plural parallel power supplies.

Abstract: A modular power supply system incorporating a power status signal generator circuit to detect the voltage sag of the input peak voltage within a short period is proposed. The power status signal generator circuit mainly includes a peak detector that detects a peak value of an input voltage, wherein the peak detector comprises a first comparator that compares the input voltage with a predetermined reference voltage and sends an output signal according to a comparison result thereof, a RC network connected to the first comparator and is configured to charge and discharge the capacitor according to the output signal of the first comparator, and a second 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 a power status signal according to a comparison result thereof.