Patent ID: 9653998
Date: 2017-05-16
CPC Classifications: H02M

Claim:
1. A boost converter including a power input end and an output end, comprising: a first switch unit; a second switch unit; a pulse width modulation (PWM) circuit for controlling the first switch unit and the second switch unit to turn-on or turn-off, an inductor coupled to the first switch unit and the second switch unit, wherein the inductor is controlled by switch-states of the first switch unit and the second switch unit, to store energy received from the power input end or to release energy stored in the inductor to the output end selectively; a discharging loop connected with the inductor in parallel and including a third switch unit; an auxiliary loop connected in parallel with the second switch unit, and the auxiliary loop including a diode and a fourth switch unit, the diode and the fourth switch unit being connected in series; a detecting circuit for detecting a discharging value of the inductor; and a logic circuit coupled to the detecting circuit and the fourth switch unit, wherein when the discharging value is less than the threshold value, the logic circuit turns off the third switch unit and turns on the fourth switch unit, and when the discharging value is larger then the threshold value, the logic circuit turns on the third switch unit and turns off the fourth switch unit.