Direct current-direct current switching circuit

Abstract

The invention provides a direct current-direct current switching circuit. The direct current-direct current switching circuit comprises a voltage input end, a first voltage output end, a second voltage output end, a first switch, a second switch, a first diode, a second diode, an inductor, a capacitor and a duty ratio control circuit, wherein the voltage input end is connected with the second voltage output end; the capacitor is connected between the first voltage output end and the second voltage output end; the first switch and the first diode are connected in series between the voltage input end and a ground node; the second diode and the second switch are connected in series between the first voltage output end and the ground node; the inductor is connected between two connecting nodes; one of the connecting nodes is between the first switch and the cathode of the first diode, while the other one is between the second switch and the anode of the second diode; the duty ratio control circuit drives the first switch and the second switch to simultaneously turn on or turn off. Compared to the prior art, the direct current-direct current can meet the requirement of a circuit system that sometimes the positive voltage is required, and sometimes the negative voltage is required.

Description

【Technical field】 [0001] The invention relates to the field of circuit design, in particular to an inductance-based DC-DC conversion circuit. 【Background technique】 [0002] Conventional DC-DC converters generally can only generate positive voltages or only negative voltages. Please refer to figure 1 As shown, it is a schematic circuit diagram of a step-down DC-DC converter in the prior art. The step-down DC-DC converter includes a switch S1 connected between a voltage input terminal VIN and a ground node, an inductor L1, a capacitor C1, and a diode D1, wherein the anode of the diode D1 is connected to the ground node, and the cathode of the diode D1 is connected to the switch. The connection node between S1 and the inductor L1 is connected; the connection node between the inductor L1 and the capacitor C1 is used as the voltage output terminal VO of the step-down DC-DC converter. figure 1 The voltage value of the voltage output terminal VO of the shown DC-DC converter is ...

AI Technical Summary

Problems solved by technology

[0004] But in some occasions, it is necessary to generate both positive voltage and negative voltage. For example, to drive the rotor to rotate, if the rotor needs to rotate counterclockwise, it will generate positive voltage drive; if the rotor needs to rotate clockwise, it will generate negative voltage drive. In this way, in the prior art, two sets of conversion circuits are required to generate positive voltage and negative voltage respectively and combined control is required, resulting in complicated circuit structure

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