DC/DC converter

Abstract

There is provided a DC-DC converter including: a main switching element to perform an on-off operation; a first choke coil; an output capacitor; and a diode module. The diode module includes a first series circuit which includes an auxiliary switching element and a resonant capacitor, and a second series circuit which includes a flywheel diode and a resonant coil, wherein the first series circuit and the second series circuit are connected in parallel to each other. The DC-DC converter reduces the switching loss, deals with an extensive range of input and output voltage variation, and accommodates easy modifications from conventional circuits.

Description

technical field [0001] The present invention relates to a DC-DC converter, and in particular to a DC-DC converter incorporating diode modules so as to be able to reduce switching losses. Background technique [0002] Through switching control of semiconductor devices, the DC-DC converter converts the input DC voltage into a desired stable DC voltage, which has the advantages of high efficiency and easy reduction in size and weight, and therefore, in the control of inverter technology-based In electric motors and in circuits that light various discharge lamps, DC-DC converters are used as basic components in the power supply of various electronic devices. [0003] FIG. 16 is a circuit diagram of a typical step-down DC-DC converter 100 . The DC-DC converter 100 includes a field effect transistor Q1 as the main switching element, a freewheeling diode D3, a choke coil L1, an output capacitor C5 and a control circuit 102, where the voltage Vi is the DC power source, R1 is the lo...

AI Technical Summary

Problems solved by technology

[0009] However, in the DC-DC converter disclosed in the aforementioned Japanese Patent Application, when the duty ratio is set small, the resonant coil cannot accumulate sufficient energy, thus causing the voltage of the resonant capacitor to decrease.

If this condition continues, the voltage polarity of the resonant capacitor is reversed and the resonant coil cannot be reset

In addition, in the DC-DC converter, a rectification circuit composed of a rectification diode (freewheel diode) and an additional part for resonance is constructed so that only the resonance coil is located between the first switching element and the choke coil, and Other components are connected in parallel to the resonant coil, and thus if the rectification circuit is made as a module, the circuit will have at least three terminals, which is not conducive to modifying the conventional circuit using a freewheeling diode as a two-terminal element

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