Slope compensation circuit with frequency self-adaptation function

Abstract

The invention discloses a slope compensation circuit with a frequency self-adaptation function, which mainly solves the problem that the existing slope compensation circuit has fixed current gradient for slope compensation and can not adaptive to different system frequencies. The slope compensation circuit comprises a slope voltage generation module, a voltage-to-current conversion module and a frequency self-adaptation module. An input / output end VCAP (voltage capacitor) of the slope voltage generation module is respectively connected to an output end of the frequency self-adaptation module and an input end of the voltage-to-current conversion module. The frequency self-adaptation module is composed of a direct current component extraction unit, a level shifting unit and a transconductance amplification unit; an input end of the direct current component extraction unit is connected with a working clock signal OSC (Open Source Commerce) of a DC-DC while an output end of the direct current component extraction unit is connected to an inverse phase input end of the transconductance amplification unit to generate a current signal IS2 capable of reflecting the frequency change of the clock signal OSC, so that the gradient of the signal output by the whole slope compensation circuit can be automatically adjusted according to the frequency of the working clock signal OSC, so as to realize frequency self-adaptation.

Description

technical field [0001] The invention belongs to the field of analog integrated circuit design, in particular to a frequency self-adaptive slope wave compensation circuit, which can be used in a current mode DC-DC converter. Background technique [0002] The DC-DC switching power supply using current mode control adds a current sampling loop on the basis of traditional voltage mode control, which significantly enhances the dynamic characteristics of the DC-DC system. Current mode control is divided into peak current mode control and valley current mode control according to different feedback loop designs. However, no matter in the peak current mode when the working duty cycle is greater than 50% or in the valley current mode when the working duty cycle is less than 50%, sub-harmonic oscillations will appear in the DC-DC system. Therefore, it is necessary to add a slope compensation circuit in the current sampling loop to achieve good stability of the current loop. The slope...

AI Technical Summary

Problems solved by technology

However, this slope compensation circuit can only generate a slope compensation signal with a fixed slope. Once the DC-DC operating frequency changes, the originally set slope cannot continue to match the new frequency, so that the current loop cannot continue to be stable, which limits the DC-DC. Application range of DC

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