DC-DC CONVERTER

摘要

A DC-DC converter includes a switching device, a drive circuit for turning on and off the switching device, a bootstrap capacitor electrically connected to the drive circuit, and a control circuit electrically connected to the drive circuit. The control circuit is operable to charge the bootstrap capacitor for a charging duration periodically at a charging period longer than an on-off period at which the switching device is turned on and off periodically. This DC-DC converter performs efficient boost and step-down operations.

主权项

1. A DC-DC converter configured to output an output voltage obtained by converting an input voltage, comprising:
an input terminal that has the input voltage applied thereto; an output terminal that outputs the output voltage; a ground terminal; a first switching device electrically connected in series between the input terminal and a first node; a second switching device electrically connected in series to the first switching device at the first node and between the first node and the ground terminal; a first drive circuit that turns on and off the first switching device; a first bootstrap capacitor circuit including a first bootstrap capacitor electrically connected to the first drive circuit; a second drive circuit that turns on and off the second switching device; a third switching device electrically connected in series between the output terminal and a second node; a fourth switching device electrically connected in series to the third switching device at the second node and between the second node and the ground terminal; a third drive circuit that turns on and off the third switching device; a second bootstrap capacitor circuit including a second bootstrap capacitor electrically connected to the third drive circuit; a fourth drive circuit that turns on and off the fourth switching device; an inductor electrically connected in series between the first node and the second node; and a control circuit electrically connected to the first drive circuit, the second drive circuit, the third drive circuit, and the fourth drive circuit, wherein, in a case that the output voltage is lower than the input voltage, the control circuit is operable to control the first drive circuit, the second drive circuit, the third drive circuit, and the fourth drive circuit as to:
turn on and off the first switching device and the second switching device alternately and periodically at a first on-off period;turn off the third switching device and turn on the fourth switching device so as to charge the second bootstrap capacitor for a first charging duration periodically at a first charging period longer than the first on-off period; andturn on the third switching device and turn off the fourth switching device for a duration in the first charging period other than the first charging duration periodically at the first charging period, and wherein, in a case that the output voltage is higher than the input voltage, the control circuit is operable to control the first drive circuit, the second drive circuit, the third drive circuit, and the fourth drive circuit as to:
turn on and off the third switching device and the fourth switching device alternately and periodically at a second on-off period;turn off the first switching device and turn on the second switching device so as to charge the first bootstrap capacitor for a second charging duration periodically at a second charging period longer than the second on-off period; andturn on the first switching device and turn off the second switching device for a duration in the second charging period other than the second charging duration periodically at the second charging period.