Bootstrap Capacitor Detecting Circuit and Bootstrap DC-DC Converter Thereof

A bootstrap DC-DC converter, comprising:

• a bootstrap capacitor;
• an upper gate driving unit, comprising an input terminal of a driving voltage coupled to a bootstrap voltage node;
• and
• a bootstrap capacitor detecting circuit, comprising:
• a current source, for providing a discharging current;
• a first switch, coupled between a system voltage and a bootstrap voltage node, for conducting connection between the system voltage and the bootstrap voltage node according to a power-on-reset signal, to charge the bootstrap voltage node;
• a second switch, coupled between the current source and the bootstrap voltage node, for conducting connection between the current source and the bootstrap voltage node according to the power-on-reset signal, to discharge the bootstrap voltage node;
• and
• a detecting unit, for determining whether a bootstrap capacitor is connected normally according to a bootstrap voltage of the bootstrap voltage node after the current source discharges the bootstrap voltage node.