Patent ID: 8779739

Claim:
A DC converter for converting a first supply voltage into a second supply voltage, the first supply voltage being higher than the second supply voltage, the DC converter comprising: a driving stage comprising a modulation circuit, a pull-up driving unit, and a pull-up unit, wherein the modulation circuit generates a control signal according to the second supply voltage, the pull-up driving unit generates a first P-type driving signal and a second P-type driving signal according to the control signal, and the pull-up unit comprises a first P-type transistor and a second P-type transistor, wherein the second P-type transistor has a source terminal electrically connected to the first supply voltage, and a gate terminal receiving the second P-type driving signal, wherein the first P-type transistor has a source terminal electrically connected to a drain terminal of the second P-type transistor, a gate terminal receiving the first P-type driving signal, and a drain terminal electrically connected to a driving stage output terminal; and an output stage for generating the second supply voltage according to an output voltage of the driving stage output terminal, wherein during a transient period of switching the output voltage of the driving stage output terminal from a third supply voltage to the first supply voltage, the first P-type driving signal is decreased from a first bias voltage to a second bias voltage, wherein during a stable period after the transient period, the first P-type driving signal is restored to the first bias voltage.