Method for improving cross regulation rate of multi-path output switching power supply

Abstract

The invention particularly relates to a method for improving the cross regulation rate of a multi-path output switching power supply. According to the technical scheme of the method for improving the cross regulation rate of the multi-path output switching power supply, a secondary main output winding Ns1 circuit switching tube is connected in parallel with an RCD absorption circuit. The RCD absorption circuit comprises a resistor R2, a capacitor C2 and a rectifier diode D3. The resistor R2 and the capacitor C2 are connected in series and then are connected in parallel with the rectifier diode D3. The RCD absorption circuit absorbs the leakage inductance voltage spike at the secondary conduction instant. Based on the method for improving the cross regulation rate of the multi-path output switching power supply, the RCD absorption circuit is arranged on the secondary output winding side so as to directly absorb and suppress the leakage inductance voltage spike of a secondary output winding. Therefore, the absorption effect of the method is better than that of the primary side voltage clamp control. At the same time, in combination with a primary side clamp circuit, the leakage inductance voltage spike and the leakage inductance energy coupling of a transformer can be further reduced. The stability of the auxiliary output voltage is improved. Moreover, the cross regulation rate of the multi-path output switching power supply is improved.

Description

technical field [0001] The invention relates to the technical field of power supply circuit design, in particular to a method for improving the cross regulation rate of a multi-channel output switching power supply. Background technique [0002] Multi-output switching power supplies are widely used as power supplies for some complex electronic systems. In the design, the one with low output voltage and large output current range is usually used as the main circuit for feedback adjustment control to maintain the stability of the output voltage when the input voltage and load change. Ideally, the auxiliary output voltage and the main output voltage satisfy the transformer turn ratio relationship, that is, as long as the main output voltage is kept stable, the auxiliary output voltage can also be kept stable. But in fact, due to the influence of the leakage inductance between the windings of the transformer, winding resistance, loop parasitic parameters, etc., the auxiliary ou...

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Problems solved by technology

However, since this method is an indirect suppression of the secondary leakage inductance, the effect is limited

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