Patent ID: 8026705
Filing Date: 2011-09-27
Classification: H02M

Abstract:
1. A bootstrap circuit, applied in a bulk circuit, the bulk circuit having an inductor, a diode, a voltage divider, a switch control circuit, a gate driving circuit, and a first transistor, the inductor having a first end and a second end, for generating an output voltage, the diode coupled between the first end of the inductor and a first voltage source, the voltage divider coupled between the second end of the inductor and the first voltage source, for generating a feedback voltage according to a partial voltage of the output voltage, the switch control circuit for generating a first, a second and a third switch control signals according to the feedback voltage, the gate driving circuit coupled to the switch control circuit for generating a driving switch control signal according to the first switch control signal, the first transistor having a first end coupled to a input voltage source, a second end coupled to the first end of the inductor, and a control end coupled to the gate driving circuit, the first transistor coupling the first end of the first transistor to the second end of the first transistor according to the gate driving signal, the bootstrap circuit comprising: a second transistor, comprising: a third transistor, comprising: a fourth transistor, comprising: an offset capacitor, comprising: