Regulator device and control method thereof

A method of controlling a regulator device, wherein the regulator device comprises a first switch, a second switch, and a controlling circuit, a control terminal of the first switch configured to receive a first control signal, a first terminal of the second switch coupled with a second terminal of the first switch at a node, a control terminal of the second switch configured to receive a second control signal, wherein the method comprises:

• outputting, by the controlling circuit, the first control signal with a first slope to the first switch during a first period;
• and
• outputting, by the controlling circuit, the first control signal with a second slope to the first switch during a second period according to a decrease in a voltage of the node, wherein the first period is less than the second period, and the first slope is larger than the second slope,
• wherein the control terminal of the second switch receives the second control signal in a third period only and does not receive the second control signal in the first and second periods, wherein the third period is later than the first and second periods;
• wherein the method further comprises:
• entering the first period when the controlling circuit receives a disable signal for turning off the first switch, wherein the first switch is turned off by the controlling circuit using the first control signal with the first slope, which is larger than the second slope, during the first period;
• detecting the voltage of the node by the controlling circuit, and entering the second period when the voltage of the node is equal to a first threshold voltage, wherein the first switch is turned off by the controlling circuit using the first control signal with the second slope, which is less than the first slope, during the second period;
• and
• detecting the voltage of the node by the controlling circuit, wherein when the voltage of the node is equal to a second threshold voltage, the controlling circuit prepares outputting the second control signal for turning on the second switch.