DC/DC converter, power converter and control method thereof

摘要

A DC/DC converter, a power converter and a control method thereof are disclosed, wherein the DC/DC converter includes an output circuit, a rectangular wave generator, a resonant tank, a detection unit and a control unit. The output circuit has a load. The rectangular wave generator converts an input voltage into driving pulses. The resonant tank provides a first voltage based on the driving pulses for the output circuit. The detection unit detects a signal related to a state of the load. When the state of the load is a light-load or a no-load, the control unit controls the rectangular wave generator in a hiccup mode to reduce a ratio of a work period to a stop period, or makes that number of the driving pulses within the current work period is less than the number of the driving pulses when a duty ratio is 50%.

主权项

1. A DC/DC converter comprising:
an output circuit having a load; a rectangular wave generator for converting an input voltage into driving pulses; a resonant tank for providing a first voltage based on the driving pulses for the output circuit; a detection unit for detecting a signal related to a state of the load; and a control unit for controlling the rectangular wave generator in a hiccup mode to reduce a ratio of a current work period to a stop period when the state of the load is a light-load or a no-load, wherein the ratio of a current work period to a stop period in the light-load or the no-load is smaller than a ratio of a current work period to a stop period when the duty ratio is 50% in the light-load or the no-load wherein a working frequency of the driving pulses is higher than a resonance frequency of the resonance tank, and the duty ratio of the driving pulses is within a predetermined range, so that a voltage gain of the DC/DC converter is higher than another voltage gain under the condition of 50% duty ratio.