Current-Based Switching Frequency Automatic Regulator in Buck Circuit

Abstract

The invention discloses a switching frequency automatic regulating device based on current in a Buck circuit. The switching frequency automatic regulating device comprises a pulse width modulation (PWM) control module for outputting PWM signals, a switching module for outputting switching signals under control of the PWM signal, a current detection module for detecting output current of the switching module, a current value conversion module for obtaining a current value of the output current detected by the current detection module, a control module for selecting corresponding control signals according to the current value of the output current so as to output the control signals and a frequency adjusting module for adjusting control frequency of the PWM signals output by the PWM control module according to the control signals. According to the switching frequency automatic regulating device, the corresponding control signals are selected according to the current value detected by the current detection module, adjustment of the PWM signals output by the PWM control module is achieved, frequency of the switching signals output by the switching module is adjusted, and conversion efficiency of the Buck circuit is improved.

Description

technical field [0001] The invention relates to the technical field of Buck circuits, in particular to a test method and a test device for an asynchronous system. Background technique [0002] In the Buck (step-down conversion) circuit, since the component parameters are fixed, the conversion efficiency and the quality of the output voltage waveform are reduced when facing different current load conditions. When the load is very low current, the Buck circuit changes from a continuous working mode to a discontinuous mode, and the traditional Buck circuit will cause the problem of closed-loop instability. [0003] After the traditional Buck circuit is designed, the switching frequency and component parameters are fixed. However, in the design, it is necessary to design according to the maximum value of the circuit power, and in practical applications, the circuit works at 60% or even lower than the design specification. At this time, according to the calculation formula of th...

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Problems solved by technology

However, in the design, it is necessary to design according to the maximum value of the circuit power, and in practical applications, the circuit works at 60% or even lower than the design specification. At this time, according to the calculation formula of the power consumption of the voltage conversion current, the switching loss of the circuit will be Gradually increase its proportion in the overall power consumption, thereby affecting the efficiency of the conversion circuit

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