Power conversion circuit, related device and terminal device

Abstract

The embodiment of the invention provides a power conversion circuit, a related device and a terminal device. The power conversion circuit is used for converting the power supply and providing a low-voltage working power to a load. The power conversion circuit comprises a first switch branch, a second switch branch, a third switch branch, a filter branch and a first capacitor, wherein the first endof the first capacitor is connected with the power source through the first switch branch, the second end of the first capacitor is grounded through the second switch branch; the filtering branch comprises a filtering inductor and a filtering capacitor which are connected in series, the first end of the filtering inductor is connected with the first end of the first capacitor; the second end of the filter inductor is connected with the first end of the filter capacitor, and the second end of the filter capacitor is grounded; the filter capacitor is connected with the load in parallel; the third switch branch is connected between the second end of the first capacitor and the second end of the filter inductor. According to the embodiment of the invention, the conversion efficiency of the power conversion circuit can be improved.

Description

technical field [0001] The present invention relates to the field of electronic technology, in particular to a power conversion circuit, related devices and terminal equipment. Background technique [0002] In recent years, lithium batteries have been widely used because of their high energy density, safety and reliability. As the storage capacity of lithium batteries increases year by year, fast and efficient charging of lithium batteries has become a research hotspot. [0003] The core part of the battery charging system is the power conversion circuit. The function of this circuit is to transfer the energy from the high-voltage power supply to the battery according to the needs of the battery. When energy is transferred to the battery, there will be energy loss, and the lost energy will be converted into heat to heat up the charging system. In order to reduce energy loss, it is necessary to improve the conversion efficiency of the power conversion circuit. [0004] Such ...

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Problems solved by technology

[0007] It should be noted that, on the one hand, figure 1 When the shown power conversion circuit reaches a steady state, due to the inductor current I L equal to the load current I out , when the load current I out When it is determined, the method of reducing the loss of DCR can only be realized by reducing DCR. However, due to the limitation of physical technology, it is difficult to reduce DCR, and reducing DCR will increase the price and size of inductors.

On the other hand, to lower the L X The loss of parasitic capacitance at the place, the only way is to reduce the C p , however, reducing C p It is necessary to reduce the size of the power tube switch, which will lead to an increase in the internal resistance of the power tube switch, thereby increasing the loss of the internal resistance of the power tube switch, so that even if the C p , the conversion efficiency of the final power conversion circuit may not be improved

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