DC/DC converter capable of automatically adjusting minimum fixed output current in semi-control state

Abstract

The invention provides a DC / DC converter capable of automatically adjusting the minimum fixed output current in a semi-control state, wherein the characteristic that the cathode voltage of an integrated circuit TL431 can jump is utilized, and the DC / DC converter can achieve a new function. In a multi-output semi-control secondary loop of the DC / DC converter, the change in the voltage of a divider resistor is monitored, so that the cathode voltage of the integrated circuit TL431 is changed, the working state of fixed power resistors and PNP triodes, which are connected between positive outputs and negative outputs in series, is changed, and the requirement that the minimum fixed output current in the semi-control state can be adjusted automatically is met. The DC / DC converter capable of automatically adjusting the minimum fixed output current in the semi-control state overcomes the shortcoming that in the prior art, only one or two aspects instead of all the aspects of precision, stability, complexity, efficiency, user-friendliness and the like can be taken into account in an output voltage instability solution for the multi-output semi-control secondary loop of the DC / DC converter, and all the aspects are integrated while the requirements that the size be small and technical indexes be met are met.

Description

technical field [0001] The present invention relates to analog electronics DC / DC converter technology. Background technique [0002] The development trend of modern electronic systems is becoming more and more miniaturized and complicated, and the internal power supply equipment is also required to be miniaturized. Multi-position and multi-level power supplies are gradually concentrated in one module. Features such as small size and low cost are widely used in low-power electronic equipment. [0003] In the traditional multi-channel DC / DC converter, the low-voltage and high-current one is used as the main circuit, and the sampling feedback control is performed on it, and the voltage output accuracy is very high; the remaining low-current and high-voltage outputs are used as auxiliary circuit outputs, and the output voltage is controlled by the transformer. The turn ratio and the duty cycle of the main circuit belong to the semi-control state. The output voltage accuracy of...

AI Technical Summary

Problems solved by technology

[0013] To sum up, when the whole machine requires small size, high reliability, low cost, "fool type", and the accuracy of the main road is high and the accuracy of the auxiliary road is slightly poor, the active method is not suitable for the requirements of small size and low cost. ; The above passive method is not suitable for the requirements of "fool type", high precision of main road and slightly poor precision of auxiliary road

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