Digital peak current control device

Abstract

A digitalized peak current control device comprises a sampling circuit, a given circuit, a single chip microcontroller, a digital-analog converting circuit, a rectifying circuit, and a peak current control circuit; the peak current control circuit comprises a first comparator, a first latch, and a first AND gate; the single chip microcontroller comprises a first output end for outputting a first PWM signal and a second output end for outputting a second PWM signal; the single chip microcontroller is used for figuring out a digital signal based on an output voltage and an output current collected by the sampling circuit, and a reference signal output by the given circuit; the digital-analog converting circuit is used for converting the digital signal into an analog signal and outputting the analog signal to the first comparator; the rectifying circuit is used for rectifying an input current collected by the sampling circuit, and outputting the rectified input current to the first comparator via the output end of the rectifying circuit; a level signal output from the output end of the first AND gate is used for controlling the on and off states of a switch tube of a switching power supply. The digitalized peak current control device has the advantages of low cost, high reliability, and the like.

Description

technical field

[0001] The invention relates to a digital peak current control device applied to a switching power supply. Background technique

[0002] In the voltage-type control technology, in order to solve the magnetic bias problem of the transformer, an effective solution is the DC blocking capacitor technology. Although the DC-blocking capacitor technology can solve the magnetic bias problem of the transformer, the capacitor used here has high operating frequency and large current, and there are reliability problems. The peak current control technology controls the current flowing in the positive and negative directions of the transformer to ensure that the peak values ​​are equal, that is, to ensure the magnetic balance in the two directions, and to solve the problem of the magnetic bias of the transformer from the source. The peak current control technology improves the reliability of the system while reducing the cost. Therefore, peak current technology has been ...

Images