Buck power converter capable of improving interactive interference and method thereof

Abstract

The invention discloses a method for improving the interactive interference of a buck power converter. The power converter comprises a first switching stage and a second switching stage, wherein the first switching stage converts an input voltage into a first output voltage, and the second switching stage converts the first output voltage into a second output voltage. The method is characterized in that the method comprises the following steps: 1. according to a reference voltage and a feedback voltage, producing an error signal, wherein the feedback voltage is the function of the second output voltage; and 2. producing a forward feed signal to the first switching stage from the error signal so as to stabilize the first output voltage. In the invention, the buck power converter capable of improving interactive interference and the method thereof have the advantage of improving the interactive interference between the output ends of the power supplies.

Description

technical field [0001] The present invention relates to a power supply, in particular to a step-down power converter for improving cross-interference between output ends of the power supply and a method thereof. Background technique [0002] figure 1 A conventional buck power converter 10 is shown, which includes an input terminal Vin connected to a high voltage of 12V and three output terminals Vout1 , Vout2 and Vout3 respectively providing voltages of 5V, 3.3V and 1.8V. figure 2 A simplified voltage conversion circuit 12 is shown to illustrate how to convert the input voltage Vin to the output voltage Vout1. In the circuit 12, the upper bridge switch 14 and the lower bridge switch 16 are connected in series between the input voltage Vin and the ground terminal GND. The switch 14 and 16 are respectively controlled by pulse width modulation (Pulse Width Modulation; PWM) signals 18 and 20 to alternately switch, thereby generating inductor current IL to charge capacitor C th...

AI Technical Summary

Problems solved by technology

[0005] Another two-stage power converter is proposed in U.S. Patent No. 7,026,800, which also includes a first conversion stage that converts an input voltage into a modulated voltage as the input of a second conversion stage, but the modulation The variable voltage is not used as the output of the power converter, so the two-stage power converter does not have the problem of mutual interference between the output terminals, but the output of the first conversion stage of the power converter is also tantamount to waste Dropped, it's not economical

[0006] Therefore, there are above-mentioned inconveniences and problems in the method for eliminating mutual interference between the known power converter output terminals.

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