Patent ID: 8058855

Claim:
A direct current converter for converting an input voltage to an output voltage comprising: a first node; a second node; an input voltage terminal, for receiving the input voltage; an output voltage terminal, for outputting the output voltage; a bootstrap source terminal, coupled to a high-potential voltage; a low-voltage terminal, coupled to the lowest voltage; a control module, for generating a control signal; a driving-stage circuit, coupled to the input voltage terminal, the first node, the second node, the control module and the low-voltage terminal, for being driven by a voltage of the first node, the input voltage and the low-potential voltage, to convert the input voltage to a switching signal and output the switching signal to the second node; an output-stage circuit, coupled to the second node and the output voltage terminal, for converting the switching signal to the output signal; and a bootstrap circuit, comprising: a bootstrap capacitor, coupled between the first node and the second node; a fault detector, for outputting a switch signal; and a cascade unit, coupled to the bootstrap source terminal, the first node, the control module and the fault detector, for controlling a connection between the bootstrap source terminal and the first node according to the switch signal and the control signal.