Dc-dc converting controller

A DC-DC converting controller, coupled to an output stage and an external resistor network and providing a pulse-width-modulation signal to control the output stage to provide an output voltage, the DC-DC converting controller comprising:

• a sensing circuit, coupled to the output stage and providing a sensing current;
• a droop current circuit, coupled to the sensing circuit and providing a droop current according to the sensing current;
• a first pin, coupled to the droop current circuit and the external resistor network and receiving the droop current and a first reference voltage, wherein the first pin provides the droop current to the external resistor network to make the external resistor network provide a second reference voltage;
• and
• a pulse-width-modulation signal control loop, coupled to the external resistor network and generating the pulse-width-modulation signal according to the second reference voltage and a feedback voltage related to the output voltage,
• wherein the droop current is reduced to a default value with a default time.